Document text
U.S. Department of the Interior
U.S. Geological Survey
Field Manual of
Wildlife Diseases
General Field Procedures and Diseases of Birds
lUSGS
9cience for a changing work!
U.S. Department of the Interior
U.S. Geological Survey
Field Manual of
Wildlife Diseases
General Field Procedures and Diseases of Birds
Biological Resources Division
Information and Technology Report 1999-001
DISTRIBUTION STATEMENT A
Approved for Public Release
Distribution Unlimited
Milton Friend and J. Christian Franson, Technical Editors
Elizabeth A. Ciganovich, Editor
Phillip J. Redman, Design and layout
Rosemary S. Stenback, Illustrator
BfnC QTTALriT flISFBOfEZ) 8
19991229 033
U.S. Department of the Interior
Bruce Babbitt, Secretary
U.S. Geological Survey
Charles G. Groat, Director
Major funding support was provided by the U.S. Fish and Wildlife Service,
Division of Federal Aid, Administrative Grant No. AP95-017.
Washington, D.C. _ _
Any use of trade, product, or firm names in this publication is for descriptive purposes only and does
not imply endorsement by the U.S. Government.
To order copies of this book telephone the Superintendent of Documents Telephone Order Desk at
202-512-1800 Monday through Friday from 7:30 a.m. to 4:30 p.m. Eastern time. Or visit
http://www.gpo.gov/sales and enter the title in the Sales Product Catalog search box.
For additional information about this book:
USGS
Biological Resources Division
National Wildlife Health Center
6006 Schroeder Road
Madison, Wl 53711
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Library of Congress Cataloging-in-Publication Data
Field manual of wildlife diseases : general field procedures and
diseases of birds / Biological Resources Division.
p. cm. — (Information and technology report ; 1999-001 )
Includes bibliographic references
ISBN 0-607-88096-1 (alk. paper)
1, Birds-Diseases Handbooks, manuals. 2. Wildlife diseases
Handbooks, manuals, etc. I. Geological Survey (U.S.). Biological
Resources Division. II. Series.
SF994.F54 1999
639.978— dc21 99-25869
CIP
Dedication
We dedicate this Manual to the countless field biologists within the U.S. Fish
and Wildlife Service and the State wildlife agencies with whom we have had the
privilege of working for nearly a quarter-century. Their endless assistance and
devotion to the conservation of our Nation’s wildlife resources has stimulated
our own efforts to address wildlife health issues and made those efforts more
rewarding than we originally believed was possible. We thank you for your
efforts and hope that the material provided within these pages will be useful to
you in the days ahead.
Milton Friend and J. Christian Franson
Acknowledgements
This publication was made possible through the generous contributions of time and effort by many
individuals, and we offer our sincere thanks to all. The following people are particularly deserving of
recognition. Ms. Debra Ackers endured much from us in typing draft manuscripts, making countless
adjustments to the drafts, organizing and maintaining project files, tracking the progress of the many
components of the Manual, arranging meetings among individuals involved with this project, and
assisting in many other ways — always with a smile. Her contributions were invaluable. Dr. Louis N.
Locke deserves special recognition for his technical input and laborious review of the draft manu¬
script. We thank Dr. James R. March and Ms. Barbara C. Scudder for contributing their time to read
and conunent on the final draft. Mr. Scott Hansen assembled the lists of chemicals and birds for
Appendices E and G, respectively, and assisted us in locating many of the photographs used to
illustrate the Manual. Ms. Kathryn Cleary, Ms. Karen Cunningham, and Mr. Harold Rihn provided
tabulations of information from the National Wildlife Health Center database that were used in many
of the graphics and tables. We thank the following individuals for helpful and timely reviews of various
parts of the Manual: Dr. Donald Anderson, Mr. Tom Augspurger, Dr. Val Beasley, Dr. Rebecca Cole,
Dr. Guy Connolly, Mr. Terry Creekmore, Mr. Doug Docherty, Mr. Monte Garrett, Dr. Robert Hallock,
Dr. Larry Hansen, Dr. Wallace Hansen, Dr. Tuula Hollm6n, Dr. David Jessup, Dr. Ken Langelier,
Dr. Linda Lyon, Dr. Pierre Mineau, Dr. Patrick Redig, Dr. Milton Smith, Mr. Stanley Wiemeyer, and
Dr. Thierry Work. We apologize in the event that we have failed to acknowledge some individuals who
have assisted with this project over the extended period of time required for its completion.
IV
Foreword
DO WILDLIFE DISEASES REALLY MATTER? The waterfowl manager who wakes up one morning to find ten thousand
dead and dying birds in the marsh would think so. Yet virtually every wild bird and mammal harbors at least a few parasites
seemingly without obvious adverse consequences. Parasites, viruses, bacteria, and fungi are component parts of the ecosys¬
tems in which wildlife are found, but do not necessarily cause disease. Millennia of coevolution have engendered a modus
vivendi that assures the survival of both host and parasite populations.
Then why the ten thousand sick and dying birds? Ecosystems are changing. Waterfowl are concentrated on shrinking
wetlands and remain there for longer periods of time, facilitating bird-to-bird spread of the bacteria that cause avian cholera.
Or permitting the buildup of parasites in their hosts from a small, relatively benign number to massive numbers that cause
disease and death. Water quality of wetlands changes, favoring the production of deadly botulinum toxin by bacteria and its
mobilization up the food chain to waterfowl. New, totally artificial habitats are created with unpredictable results. The ex¬
treme temperature, salinity, and other conditions of the Salton Sea have created an unusual ecosystem in which botulism
occurs in fish and in birds through biological cycles that are not yet understood. Wetland loss in southern California leaves
few alternative places for waterbirds to go, so they are attracted to the Salton Sea.
Behavior changes. Mallard ducks take up residence on the ponds and lakes of city parks and lose their migratory habits.
They share these bodies of water with exotic species, such as Muscovy ducks that have also taken up residence there after
introduction by people, setting the scene for outbreaks of duck plague, and creating the risk of spread to migratory waterfowl
that also use these areas. Raccoons and skunks become well adapted to urban life, bringing rabies and canine distemper with
them into the city.
The environment changes the physiology of wild animals. Human activity introduces into wildlife habitats chemical
compounds that adversely affect physiological processes such as reproduction and immune responsiveness. These com¬
pounds become incorporated into the ecosystems, often becoming more concentrated as they move up food chains. Their
effects can influence wildlife populations. Some of these endocrine-disrupting chemicals, such as chlorinated hydrocarbons
(DDE, PCBs), interfere with normal endocrine function by mimicking natural hormones, with resulting eggshell thinning
and breakage. Effects of these chemical compounds on immune-system responses to infectious and parasitic agents are less
well understood.
What to do? Incorporating disease-prevention measures into wildlife management practices requires more information
than is usually available. The information-gathering process must begin in the field. Field biologists must monitor disease
occurrence. This Field Manual is a valuable aid in identifying the diseases that are likely to be present, and in giving guidance
on the gathering and treatment of specimens needed to establish the diagnosis in the laboratory.
But the wildlife field biologist is in a position to provide valuable information that goes beyond the collection of samples
from sick and dead individuals. Although diseased individuals are the basic unit of surveillance, the occurrence of disease
must be put into ecological perspective. A careful description of the ecological setting in which the disease is occurring, and
any changes that have occurred over time, are ultimately as important as a careful description of the lesions observed in the
individual, if the epidemiology of that disease is to be understood, and the disease prevented through sound wildlife-manage¬
ment practices.
It is my hope that the awareness of diseases affecting wildlife and the good disease-surveillance practices promoted by this
manual will spread throughout the range of the species we are trying to mange and protect. We must know more than we do
currently about disease occurrence throughout the ranges that the wildlife occupy. Many migratory species know nothing of
international boundaries. Neither do their diseases. Until we have a much more complete picture of the disease-environment
relationships of the blue-winged teal from its nesting ground in Canada, its migration route through the United States and
overwintering areas in Central America or the Cienaga Grande de Santa Marta in Columbia, sound disease-prevention man¬
agement of that species will not be possible. Similar considerations exist for other species.
Thomas M. Yuill
Madison, Wisconsin
May, 1999
V
Photo by J. Christian Franson
“Ingenuity, knowledge, and organization alter but cannot
cancel humanities vulnerability to invasion by parasitic forms
of life. Infectious diseases which antedated the emergence
of humankind will last as long as humanity itself, and will
surely remain, as has been hitherto, one of the fundamental
parameters and determinants of human history.”
(McNeill)
VI
Introduction
“When one comes into a city in which he is a stranger, he ought to consider its situation, how it lies as
to the winds and the rising of the sun; for its influence is not the same whether it lies to the north or to
the south, to the rising or to the setting sun. These things one ought to consider most attentively, and
concerning the waters which the inhabitants use, whether they be marshy and soft, or hard and
running from elevated and rocky situations, and then if saltish and unfit for cooking; and the ground,
whether it be naked and deficient in water, or wooded and well-watered, and whether it lies in a hollow,
confined situation, or is elevated and cold ...From these things he must proceed to investigate
everything else. For if one knows all these things well, or at least the greater part of them, he cannot
miss knowing, when he comes into a strange city, either the diseases peculiar to the place, or the
particular nature of the common diseases, so that he will not be in doubt as to the treatment of the
diseases, or commit mistakes, as is likely to be the case provided one had not previously considered
these matters. And in particular, as the season and year advances, he can tell what epidemic disease
will attack the city, either in the summer or the winter, and what each individual will be in danger of
experiencing from the change of regimen.”
— Hippocrates, On Airs, Water, and Places, c. 400 B.C.
I was first employed in the field of wildlife conservation in
1956 as an assistant waterfowl biologist. Had I decided then
to join some of my colleagues in preparing a manual about
the diseases of wild birds similar to this publication, the task
would have been much simpler. The number of chapters
needed would have been far less because some of the dis¬
eases described in this Manual were not yet known to exist
in free-ranging North American birds or, if they were known,
they were not considered to be of much importance. This is
especially true for diseases caused by viruses; also, organo-
phosphorus and carbamate pesticides had not come into wide
use. These types of differences are evident between this Field
Manual of Wildlife Disease — General Field Procedures and
Diseases of Birds and the Field Guide to Wildlife Diseases
— General Field Procedures and Diseases of Migratory Birds
that was published little more than a decade ago. The cur¬
rent Manual reflects both expanded knowledge about avian
diseases and an increase in both the occurrence of disease in
wild birds and the variety of agents responsible for illness
and death of wild birds.
Landscape changes and environmental conditions that are
related to them are a major factor associated with disease
occurrence in wild birds. The direct association between
environment and human health has been recognized since
ancient times and was aptly stated by Louis Pasteur, “The
microbe is nothing; the terrain everything.” Despite this well
documented relationship, which serves as a basic founda¬
tion for addressing many human and domestic animal dis¬
eases, there has been little consideration of “the terrain” as
a factor for diseases of wild birds. We must learn to “read
the terrain” in a manner similar to the teaching of
Hippocrates and apply that knowledge to disease preven¬
tion or else the next edition of this Manual a decade from
now will likely include another major expansion in the num¬
ber of diseases being addressed.
Although this Manual is much larger than the 1987 Gen¬
eral Field Procedures and Diseases of Migratory Birds the
basic format and “terrain” approach of the previous publi¬
cation were retained because of the positive comments that
were received from its users. The format, the photographs
previously used, and most of Section 1, General Field Pro¬
cedures, have been basically retained, but the text for chap¬
ters about individual diseases (Sections 2 through 8) has
been extensively reworked. This Manual also has separate
sections that address biotoxins and chemical toxins in addi¬
tion to major expansion of the number of individual dis¬
eases within the sections on bacterial, fungal, viral, and para¬
sitic diseases. The presentations in the various sections have
Facing page quote from:
McNeill, W.H., 1976, Plagues and peoples: Anchor Press/ VII
Doubleday, Garden City, N.Y., p. 291
been supplemented with introductory comments regarding
the subject area, and most sections have been highlighted
with descriptions of miscellaneous disease conditions that
may interest users and readers.
As with the 1987 publication, the focus of this Manual is
on conveying practical information and insights about the
diseases in a manner that will help National Wildlife Refuge
managers and other field personnel address wildlife health
issues at the field level. The information represents a com¬
posite of our understanding of the scientific literature, of
our personal experiences with and investigations of the vari¬
ous diseases, and of information generously provided by our
colleagues within the wildlife disease and related fields. In
presenting this information, we have borrowed freely from
all of those sources. Because this is a synoptic field manual
and not a textbook, literature citations are not provided in
support of statements. Only a small portion of the specific
literature that is the basis for the statements has been listed,
and the supplementary reading lists are intended to provide
entry into the scientific literature for more precise evalua¬
tion of specific topics.
The need to generalize and, thus, provide a practical over¬
view of complex biological situations often results in a loss
of precision for some information. We have attempted to pro¬
vide detail where it is of significant importance and have
been more general elsewhere. In all cases, we have attempted
to represent the information objectively and accurately. For
example. Appendix E presents specific brain cholinesterase
values that are supported by laboratory data for different bird
species to provide a baseline against which others can make
judgements about mortality due to organophosphorus and
carbamate pesticides. In contrast, representation of the geo¬
graphic distribution, frequency of occurrence, and species
susceptibility associated with specific diseases is of a gen¬
eral nature and is intended only for gross comparison. The
differences in these representations of general information
between the 1987 publication and this Manual are both a
positive and a negative outcome of the last decade. These
differences reflect enhanced information about disease in
wild birds as a result of expanded study (a positive outcome),
changes in disease patterns (a negative outcome due to ex¬
pansion of disease), and both, depending on the disease.
Current understanding about wild bird diseases is being
provided by those with technical knowledge about disease
processes to those with technical knowledge and steward¬
ship and conservation of our wild bird resources. Common
language has been used whenever possible to aid in this com¬
munication and to stimulate greater interest in wildlife dis¬
ease among others who may wish to read this Manual but
who may not be familiar with some of the terms. Technical
terms have been translated in a manner that we hope will be
useful for readers as they pursue additional subject matter
detail in the scientific literature. Technical terms have also
been inserted into the text and defined where they provide
value-added precision for the statements. It is my personal
hope that a decade from now, when consideration is being
given to a revision of this Manual, that a great deal of the
preparation of the revision will be done by wildlife biolo¬
gists who have become practitioners in the art of disease
prevention and control because of an enhanced understand¬
ing of disease ecology that we have all gained through our
collective efforts. The transition hoped for is no greater than
other changes that have taken place since the 1987 publica¬
tion of the original Field Guide. At that time, the National
Wildlife Health Center (NWHC) was part of the Department
of the Interior, U.S. Fish and Wildlife Service. Since then,
the Center has become part of the Department of the Inte¬
rior, U.S. Geological Survey, Biological Resources Division.
My professional situation has also changed. Those famil¬
iar with the 1987 publication will note that I was Director of
the NWHC when that publication became available. In
December 1997, Secretary of the Interior Bruce Babbitt asked
me to accept the challenge of coordinating the science ef¬
forts that will aid and guide decisions for management
actions to improve the health of the Salton Sea, California’s
largest inland body of water. Recurring major disease events
involving migratory birds at the Sea since 1994 have focused
public attention on it. These disease events became a cata¬
lyst for the expansion of efforts to improve the environmen¬
tal quality of the Sea, and in June 1998, a combined
National Environmental Policy Act (NEPA)/California
Environmental Quality Act (CEQA) process was initiated to
pursue attainment of that goal. I officially became part of
the multiagency effort to “Save the Salton Sea” with my re¬
assignment in April 1998 from Director of the NWHC to
Executive Director, Salton Sea Science Subcommittee.
Milton Friend
VIII
Table of Contents _
Section 1 General Field Procedures
Chapter 1 Recording and Submitting Specimen History Data . 3
Chapter 2 Specimen Collection and Preservation . 7
Chapter 3 Specimen Shipment . 13
Chapter 4 Disease Control Operations . 1 9
Chapter 5 Euthanasia . 49
Chapter 6 Guidelines for Proper Care and Use of Wildlife in Field Research . 53
Section 2 Bacterial Diseases
Chapter 7 Avian Cholera . 75
Chapter 8 Avian Tuberculosis . 93
Chapter 9 Saimoneilosis . 99
Chapter 1 0 Chlamydiosis . Ill
Chapter 1 1 Mycoplasmosis . 115
Chapter 12 Miscellaneous Bacterial Diseases . 121
Section 3 Fungal Diseases
Chapter 13 Aspergillosis . 129
Chapter 14 Candidiasis . 135
Chapter 15 Miscellaneous Fungal Diseases . 137
Section 4 Viral Diseases
Chapter 1 6 Duck Plague . 141
Chapter 17 Inclusion Body Disease of Cranes . 153
Chapter 18 Miscellaneous Herpesviruses of Birds . 157
Chapter 19 Avian Pox . 163
Chapter 20 Eastern Equine Encephalomyelitis . 171
Chapter 21 Newcastle Disease . 175
IX
Chapter 22 Avian Influenza .
Chapter 23 Woodcock Reovirus .
Section 5 Parasitic Diseases
Chapter 24 Hemosporidiosis .
Chapter 25 Trichomoniasis .
Chapter 26 Intestinal Coccidiosis .
Chapter 27 Renal Coccidiosis .
Chapter 28 Sarcocystis .
Chapter 29 Eustrongylidosis .
Chapter 30 Tracheal Worms .
Chapter 31 Heartworm of Swans and Geese .
Chapter 32 Gizzard Worms .
Chapter 33 Acanthocephaliasis .
Chapter 34 Nasal Leeches .
Chapter 35 Miscellaneous Parasitic Diseases .
Section 6 Biotoxins
Chapter 36 Algal Toxins .
Chapter 37 Mycotoxins .
Chapter 38 Avian Botulism .
Section 7 Chemical Toxins
Chapter 39 Organophosphorus and Carbamate Pesticides
Chapter 40 Chlorinated Hydrocarbon Insecticides .
Chapter 41 Polychlorinated Biphenyls .
Chapter 42 Oil .
Chapter 43 Lead .
Chapter 44 Selenium .
181
185
193
201
207
215
219
223
229
233
235
241
245
249
263
267
271
287
295
303
309
317
335
X
Chapter 45 Mercury . 337
Chapter 46 Cyanide . 341
Chapter 47 Salt . 347
Chapter 48 Barbiturates . 349
Chapter 49 Miscellaneous Chemical Toxins . 351
Section 8 Miscellaneous Diseases
Chapter 50 Electrocution . 357
Chapter 51 Miscellaneous Diseases . 361
Appendices
A Sample specimen history form . 369
B Sources of wildlife disease diagnostic assistance . 370
C Sources of supplies used for collecting, preserving, and shipping specimens . 373
D Normal brain cholinesterase values for different bird species . 375
E Common and scientific names of birds in text . 377
F Common and scientific names other than birds . 383
G Chemical names . 384
H Conversion table . 387
Glossary of technical terms . 389
Index . 400
XI
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Introduction to General Field Procedures
“Given the conspicuous role that diseases have played, and in many parts of the
world continue to play, in human demography, it is surprising that ecologists have
given so little attention to the way diseases may affect the distribution and
abundance of other animals and plants. Until recently, for example, ecology
textbooks had chapters discussing how vertebrate and invertebrate predators
may influence prey abundance, but in most cases you will search the index in
vain for mention of infectious diseases.” (May)
A basic premise for the preparation of this Manual is that
disease in free-ranging wildlife is of concern and that dis¬
ease prevention and control are desirable actions. However,
these are not universally held perspectives. There are those
who when confronted with disease outbreaks in free-rang¬
ing wildlife ask — “Why bother?” Also, the same individu¬
als who may reject the need for response to one situation
may demand a response to another situation. We acknowl¬
edge in this Manual the existence of this question by making
reference to it, but we do not offer a direct response. To do
so would require this Manual to address the full spectrum of
individually held values, perspectives, interests, and beliefs
within human society that form the basis for the underlying
issues which create the question of “why bother?” Those fac¬
tors would also need to be addressed within a context of the
different roles and responsibilities of public agencies, and
would need to include some additional considerations. Such
an undertaking is outside the scope and purpose of this
Manual. Although no direct response is offered, readers will
gain considerable information regarding disease occurrence
and impacts in the chapters that follow. This information
should be of value in assisting readers to address the ques¬
tions of “why bother?” from their own set of values and in¬
terests.
Section 1 of the Manual provides basic information re¬
garding general field procedures for responding to wildlife
disease events. Field biologists provide a critical linkage in
disease diagnostic work and greatly affect the outcome of
the laboratory efforts by the quality of the materials and in¬
formation that they provide. The chapters in this section are
oriented towards providing guidance that will assist field bi¬
ologists in gathering the quality of information and speci¬
mens that are needed. Readers will find information regard¬
ing what to record and how; guidance for specimen collec¬
tion, preservation, and shipment; and how to apply euthana¬
sia when such actions are warranted. Disease operations are
managed at the field level and they can be aided by general
preplanning that can be utilized when disease emergencies
arise; therefore, contingency planning is included within the
Disease Control Operations chapter. Disease control tech¬
niques, including equipment that is used, are the main focus
for this highly illustrated chapter. Section 1 is concluded with
a chapter about the proper care and use of wildlife in field
research. The guidelines provided address the continual need
to consider animal welfare in all aspects of wildlife manage¬
ment.
Quote from:
May, R.M., 1988, Conservation and disease: Conservation
Biology, V. 2, no. 1, p. 28-30.
2 Field Manual of Wildlife Diseases: Birds
Chapter 1
Recording and Submitting
Specimen History Data
History can be defined as a chronological record of signifi¬
cant events. In wildlife disease investigations, determining
the history or background of a problem is the first signifi¬
cant step toward establishing a diagnosis. The diagnostic
process is often greatly expedited by a thorough history ac¬
companying specimens submitted for laboratory evaluation.
This information is also important for understanding the natu¬
ral history or epizootiology of disease outbreaks, and it is
difficult, if not impossible, to obtain the history after the out¬
break has occurred. Detailed field observations during the
course of a die-off and an investigation of significant events
preceding it also provide valuable information on which to
base corrective actions. The most helpful information is that
which is obtained at the time of the die-off event by a per¬
ceptive observer.
What Information Should Be Collected
What seems irrelevant in the field may be the key to a
diagnosis; therefore, be as thorough as possible. Avoid pre¬
conceptions that limit the information collected and that may
imperceptibly bias the investigation. A sample specimen his¬
tory form, which lists some categories of information that
are helpful, is in Appendix A. A good description of unusual
behavior or appearance, if any, an accurate list of what spe¬
cies were affected, and the number of animals that died are
critical pieces of information. Send specimens and the writ¬
ten history to the laboratory as soon as possible. Photographs
can be helpful if they convey specific information, such as
environmental conditions during a die-off and the appear¬
ance of sick wildlife or gross lesions (Figs. 1.1, 1.2).
Figure 7. 1 Examples of poor and good photography to record
environmental conditions associated with wildiife disease prob¬
lems. (A) Landscape photo displays topography and presence
of a power line that may or may not be involved with the mor¬
tality event Neither of the major factors involved with this event
can be dearly seen. (B) Closeup photograph clearly shows
both the species involved and the peanuts that proved to be
contaminated with the mycotoxins that were the source of the
problem. (C) Closeup photograph of sick bird clearly Illustrates
clinical signs of wing and neck droop; and the snow indicates
the season.
Recording and Submitting Specimen History Data 3
Photos by Ronald Windingstad
Figure 1.2 The observer may use photography to illustrate field observations associated with wildlife morbidity and mortality.
(A) For example, when sick birds are left undisturbed or approached quietly, they often remain motionless along the water’s
edge with their heads hanging down. When startled, these birds may attempt to escape by propelling themselves with their
wings across water (B) or land (C) but are unable to fly. (D) This bird has lost the use of its legs, a common occurrence with avian
botulism and certain toxins such as organophosphorus or carbamate compounds.
The following basic infomation is helpful for diagnos- the integrity of feathers, is severe. Record recent pesticide
ing the cause and assessing the severity of a wildlife health applications and other habitat or crop management practices
problem. Waterfowl are used as an illustrative example. as well as previous disease problems in the area.
Environmental Factors Estimating Disease Onset
Determine if the start of mortality coincided with any When estimating the onset of disease, consider: (1) the
unusual event. Environmental changes such as storms, pre- earliest date when on-site activities could have resulted in
cipitation, and abrupt temperature changes are potential the detection of sick or dead birds, if they were present, and
sources of stress that can contribute to disease outbreaks. A the actual date when diseased birds were first seen, and (2)
food shortage may degrade the condition of birds and in- the proportion of fresh carcasses compared with the number
crease their susceptibility to disease. Water-level changes in of scavenged and decomposed carcasses. The abundance and
an area may concentrate or disperse birds, alter the access!- types of scavengers and predators can be used to predict how
bility of toxins in food or water, or cause an invertebrate die- long carcasses remain in the area. Other useful information
off that could lead to an avian botulism outbreak. Attempt to about the onset of mortality can be gained from noting any
determine whether or not biting insect populations have in- differences in plumage, including stage of molt, if present,
creased or if such insects are present, because some insects between live and dead birds. Size differences between live
are carriers of blood-bome infections in waterfowl. and dead nestlings and fledglings may also provide useful
The quality of the water used as a source for an impound- information for comparison with known growth rates. Also,
ment may contribute to disease or mortality; for example, air, water, and soil temperatures will affect the speed of de¬
poor water quality may contribute to avian botulism or may composition and they should be considered in assessing how
be a primary cause of mortality if water contamination by long birds have been dead. Include these observations in the
toxic materials and substances such as oil, which can affect history.
4 Field Manual of Wildlife Diseases: Birds
Photos by Milton Friend
Species Affected
Much can be learned by knowing what species are dying.
Those species present but unaffected are especially impor¬
tant to note, because some diseases infect a narrow host range
and others infect a wide variety of species. For example, duck
plague affects only ducks, geese, and swans, but avian chol¬
era affects many additional species of water birds as well.
Species with similar feeding habits may be dying as a result
of exposure to toxins, while birds with different food require¬
ments remain unaffected.
Age
Some disease agents may kill young birds but leave adults
unaffected because of age-related disease resistance; other
diseases kill birds of all ages, although young or old birds
may be more susceptible because of additional stress placed
on these age groups. When toxins are involved, differences
in food habits may result in exposure of young birds, but not
of adult birds, or vice versa.
Sex
Sex differences in mortality may be apparent in colonial
nesters where females are incubating eggs, or in other situa¬
tions where the sexes are segregated.
Number Sick/Number Dead
The longer a disease takes to kill, the more likely it is that
significant numbers of sick birds will be found. For example,
more sick birds will probably be observed during an avian
botulism die-off than during an outbreak of a more acute
disease such as avian cholera.
Clinical Signs
When observing sick birds, describe the clinical signs in
as much detail as possible. Include any abnormal physical
features and describe unusual behaviors, such as a sick bird’s
response to being approached. Photographs (Fig. 1.2) of vari¬
ous behaviors or conditions associated with a disease can be
especially useful and should be included with the history.
Population at Risk
Try to determine what species, and in what numbers, are
in the vicinity of the die-off. This information can provide
clues about the transmissibility of disease, and it may be use¬
ful during control efforts.
Population Movement
Record recent changes in the number of birds in the area,
as well as the species present. In particular note the presence
of endangered species. If bird numbers have increased, try
to determine where they came from; if bird numbers have
decreased, attempt to determine where they have gone. This
can often be accomplished when population movements are
being monitored for census, hunting forecasts, and other
purposes. State, Federal, and private refuge personnel and
other natural resources managers are good primary sources
of information.
Specific Features of Problem Areas
Describe the location of a die-off so that a relatively spe¬
cific area can be identified on a road map. Also include any
available precise location data, such as global positioning
information or data that will facilitate entering of specific
locations into geographical information system databases.
Describe the problem area in terms that are sufficiently
graphic so that someone with no knowledge of it can visual¬
ize its major characteristics, such as topography, soil, veg¬
etation, climate, water conditions, and animal and human
use.
i
I Example description of die-off iocation
I The problem area is a 1 0-acre freshwater pond located
i in Teno County, North Carolina, 1/2 mile east of County
ji KV, 5 miles north of Highway 43. The pond has an
f average water depth of 6-12 feet and a sandy substrate.
] Vegetation around the pond border is bullbrush and
j reed canary grass. The surrounding uplands are essen-
f dally flat for one-half mile in all directions and lie fal-
f low, covered with grasses and some shrubs. The area
I is coastal with enough relief to prevent saltwater in-
; trusion into the pond even during major storms.
; Weather for the past 2 weeks has been pleasant and
: there has been no precipitation. Daytime temperatures
are currently in the mid-80s (°F) and evening tempera¬
tures in the 70s. This is an isolated body of freshwater
with good clarity, and sustains several hundred water-
■ fowl, gulls, and small numbers of wading birds and
;; shorebirds, and healthy warm water fish and amphib-
) ian populations. Cattle graze the adjacent area. There
I are no residential or industrial buildings within 1 mile
I of the site. Human visitation is fi^quent for bird watch-
I ing, fishing, and hiking. Companion animals such as
I dogs are allowed on the area.
Identify where sick and dead birds are found. Especially
note the locations of groups of dead birds and any differ¬
ences of habitat where dead and sick birds are found. Birds
found in agricultural fields may be dying of pesticide expo¬
sure, birds with more chronic toxicoses usually seek dense
cover, and birds dying of acute diseases may be found in a
variety of situations. Check any relation between specific
bird use of the area and the location of affected birds, such
as roost sites, loafing areas, and feeding sites.
If followup investigations are conducted after specimens
have been submitted, summarize the findings and observa¬
tions of those investigations in a supplemental report to the
original history. Maintain a copy of the new report in station
Recording and Submitting Specimen History Data 5
files, and provide a copy to the diagnostic laboratory where
the specimens were sent. Both reports should contain the
dates of the investigations, whether air or ground searches
were performed, the number of investigators and the time
spent on the investigation, the weather conditions, and the
time of day when the site was investigated.
The insight provided by good specimen history data and
by field observations is invaluable to disease specialists. This
information enhances understanding of the ecology of dis¬
ease, thereby serving as a basis for developing ways to pre¬
vent future die-offs or to reduce the magnitude of losses that
might otherwise occur.
J. Christian Franson
Supplementary Reading
Wobeser, G.A., 1994, Investigation and management of disease in
wild animals: New York, N.Y, Plenum Press, 265 p.
6 Field Manual of Wildlife Diseases: Birds
Chapter 2
Specimen Collection and Preservation
Specimens are used to provide supporting information lead¬
ing to the diagnosis of a cause of disease or death. A speci¬
men may be an intact carcass, tissues removed from carcasses,
parasites, ingested food, feces, or environmental samples.
The specimen should be as fresh and undamaged as pos¬
sible.
Choosing a Specimen
An entire, fresh carcass is the best specimen to submit to
the laboratory for diagnosis. This allows the diagnostician
to assess all of the organ systems and to use appropriate or¬
gans for different diagnostic tests. Obtain the best specimens
possible for necropsy; decomposed or scavenged carcasses
are usually of limited diagnostic value. A combination of
sick animals that were euthanized after clinical signs were
observed and recorded, and some of the freshest available
carcasses compose an ideal specimen collection. The method
of euthanasia should not compromise the diagnostic value
of the specimen (see Chapter 5, Euthanasia). More than one
disease may be affecting the population simultaneously, and
the chances of detecting multiple diseases will be maximized
if both sick and dead animals are collected. Specimens sub¬
mitted should be representative of the species involved. If
more than one species is affected, collect several specimens
of each species; try to obtain a minimum of five specimens
per species.
Tissue Collection
The primary consideration when collecting carcasses or
tissues for diagnosis should be personal safety. Some wild¬
life diseases are transmissible to humans, and every carcass
should be treated as a potential health hazard. Wear dispos¬
able rubber or plastic gloves, coveralls, and rubber boots. If
gloves are not available, inverted plastic bags may be used
(Fig. 2.1). Before leaving an area where carcasses are being
collected, double-bag used gloves and coveralls, and disin¬
fect boots and the outside of plastic bags with a commercial
disinfectant or a 5 percent solution of household chlorine
bleach. Also, double-bag specimens in plastic before remov¬
ing them from the area. These precautions will help protect
the people in the field and minimize transmission of disease
to unaffected wildlife populations.
If it is impossible to submit an entire carcass for diagno¬
sis, appropriate organs must be removed from specimens. If
possible, do not dissect carcasses in the field without first
consulting disease specialists about methods of dissecting
and preserving tissues or parasites or both. Assistance can
be obtained from a variety of sources (Appendix B). It is
Figure 2.1 Use a plastic bag to protect hands from direct
contact with animal tissues during the collection of specimens
if plastic or other waterproof gloves are not available. (A) Grasp
bag at the bottom and (B) with other hand pull open end down
over hand holding bag (C). Repeat for the ‘"unbagged” hand.
Reversing this process when handling small specimens will
automatically place specimens in the bag, which then need
only be sealed and put into a second bag for packaging and
shipment.
Specimen Collection and Preservation 7
best to become familiar with these sources and their ability
to provide specific types of assistance before an emergency
arises. The basic supplies and equipment that should be in¬
cluded in a field kit for specimen collection will vary with
the species being sampled and the types of analyses that will
be conducted. Keep a small kit packed in a day pack for ready
use (Fig. 2.2). Sources of supplies used for collecting, pre¬
serving, labeling, and shipping specimens are listed in
Appendix C.
Whirl-Pak® bags are very effective containers for tissue
specimens. These bags have a sterile interior, are easy to carry
in the field, and can be used to hold a variety of samples
(Fig. 2.3). Specimen identification should be written directly
on the bag with an indelible marker.
If lesions are noted, collect separate tissue samples for
microscopic examination, microbiology, toxicology, and
other analyses. With a sharp knife or scalpel cut a thin (1/8-
1/4 inch, 3-6 millimeter) section of tissue that includes all
or portions of the lesion and adjacent apparently healthy tis¬
sue (Fig. 2.4). Take care not to crush tissue in or around the
lesion. Place the tissue sample in a volume of 10 percent buff¬
ered formalin solution equal to at least 10 times the tissue
volume to ensure adequate preservation. Formalin is classi¬
fied as hazardous; take appropriate measures to prevent skin
contact of vapor inhalation. Jars, such as pint or quart can¬
ning jars, are convenient containers for preservation of tis¬
sues, but wide-mouth plastic bottles (Fig. 2.5) eliminate the
potential breakage problems. After 2 or 3 days in 10 percent
formalin, tissues can be transferred to Whirl-Pak® bags that
contain enough formalin to keep the tissues wet. Write the
specimen identification with indelible marker or pencil on a
piece of index card, place the card inside the bag, and write
the information directly on the bag with indelible marker.
Pack the bags for shipping so as to prevent tissues from be¬
ing crushed. Check with the courier regarding current re¬
quirements or restrictions for shipment of formalin.
If it is necessary to collect a blood sample from a live bird
(if, for example, botulism is suspected), and syringes and
needles are not available, sever the bird’s head from its neck
and collect the blood in a wide-mouth plastic jar.
Photographing external and internal lesions provides a
record of the color, location, and appearance of lesions when
appropriate camera equipment is available. Use a macro lens,
high speed film, and a fast shutter speed to achieve maxi¬
mum depth of field and sharply focused photographs with a
hand-held camera. Include in the photograph for scale a coin
or another readily recognized indicator of actual size. Ex¬
plain on the history form submitted with the specimens what
photographs were taken.
Figure 2.2 A basic necropsy kit that can be packed into a smali day pack. Ciockwise,
from top of photo: Data recording: field notebook, tags, pencils, markers. Protective
apparel: rubber gloves, disposable shoe covers and coveralis, mask. Necropsy equip¬
ment: disinfectant for cleaning instruments, scrub brush, heavy shears, forceps, scis¬
sors, scalpel handle and blades. Measuring equipment: hanging scale and ruler. Sam¬
pling materials: microscope slides, syringes and needles, swabs, blood tubes, aluminum
foil, Whirl Pak® bags, plastic bags, wide mouth plastic jars. Preservatives: ethanol for
parasites, formalin for tissue samples.
8 Field Manual of Wildlife Diseases: Birds
Photo by James Runningen
Figure 2.5 Plastic bottles used for tissue
specimens. Regardless of size or shape,
specimen bottles should have a wide mouth
and threaded caps for secure closure.
Figure 2.3 Using Whirl-Pah® bag for specimen collection.
(A) Remove top at perforation. (B) Open bag by simultaneously
pushing the protruding wire-reinforced tabs toward the center
to insert the specimen and any appropriate preservative.
(C) Close bag by pulling on tabs and then twirling bag while
holding tabs. (D) Secure the ciosure by folding tabs around
bags and label bag with type of specimen, date, and any iden¬
tifying numbers.
Figure 2.4 Tissue sample collection for microscopic exami¬
nation. (A) Tissue sample should include lesion, such as spots
in liver, plus some apparently healthy tissue. The sample must
be no thicker than 1/4 inch to ensure adequate chemical fixa¬
tion by preservative. Use as sharp an instrument as possible
(scalpel, knife, razor) for a clean cut. (B) Place tissue sample
into container of 10 percent buffered format in or other suitabie
fixative or preservative. The volume of formalin in the con¬
tainer should be about 10 times the amount of tissue sample.
(C) Complete the process by securing the lid and properly
labeling the container.
Specimen Collection and Preservation 9
Figure 2.6 Dissecting a duck carcass: (A) incision iine; (B) refiect the skin to expose the underiying anatomy; (C) make a
transverse abdominai cut beiow the breast muscie; (D) extend cut through the ribs and wishbone; (E) remove breast piate; (F)
dissect out heart; (G) remove iiver; and (H) tie off and remove the gastrointestinai tract.
10 Field Manual of Wildlife Diseases: Birds
Trachea
Esophagus
Heart
Liver
Gall bladder
Proventriculus
Spleen
Gizzard
Pancreas
Small intestine
Large intestine
Cecum
Cloaca
Vent
Remove
gastrointestinal j/
tract
Avian Dissection
When dissecting a bird, it is always advisable to
wear protective clothing, particularly disposable
gloves. To begin, insert a scalpel or a knife to make a
midline incision through the skin of the breast (Fig
2.6 A). Take care not to penetrate the body cavity,
particularly in the abdominal region. Continue the
skin incision to the vent and to the base of the bill.
Reflect the skin away from the neck, breast, and ab¬
dominal areas. (B) Use the thumb and the first fin¬
ger of each hand to reflect the skin to expose the
underlying tissues. It is easiest to place the thumb
and the first finger of each hand along the incision
line in the breast area and then push and gently pull
the skin to the side. When an opening in the skin has
been established, work towards the bill and then the
vent. (C) With a sharp blade, make a shallow trans¬
verse incision just below the breast muscles and ster¬
num. (D) Insert the thumb of one gloved hand into
the incision along the midpoint of the sternum and
apply a slight pressure upwards. With a scissors in
the other gloved hand, carefully cut through the ribs
extending the cut on each side of the breast through
the area of the wishbone. (E) Gently separate the
breastplate from the carcass; use a scissors or other
instrument to sever any connections and push aside
the air sacs. (F) Dissect out the heart without cutting
into other tissues. (G) Gently remove the liver and
carefully cut away its area of connection with other
tissues. (H) Tie off the gastrointestinal tract near the
throat area, cut the esophagus above the tied-off area,
and gently remove the entire gastrointestinal tract.
Avian Anatomy
Figure 2.6 illustrates organs and tissues that may
exhibit various lesions and that may be sampled for
the diagnosis of disease agents described in this
Manual. Species variation may result in
some differences in the appearance and
relative size of particular organs and
tissues, but their location will be
similar among species. Notable dif¬
ferences between the types of spe¬
cies illustrated are the small flat
spleen in normal ducks and the
larger oval spleen in pheasants.
Also, pheasants have a crop and
ducks do not; instead, the area
just forward of the gizzard (the
proventriculus) is more prom-
inant in waterfowl.
Specimen Collection and Preservation 11
Labeling Specimens
Proper labeling, maintaining label readability, and pre¬
venting label separation from specimens are as critical as
proper specimen selection and preservation. The label should
be as close to the specimen as possible; for example, a label
should be attached to a carcass, attached to a tube of blood,
or placed within the vial of preservative with a parasite.
Double labeling, or placing a label on the outside of a plastic
bag holding the specimen whenever practical, is worth the
effort. The double labeling prevents confusion and potential
Figure 2. 7 Proper tagging of specimen. History of the speci¬
men (see text for details) should be placed on back of tag.
errors in specimen records at the diagnostic laboratory when
specimens are received from multiple carcasses. Manila tags
can be used, but take care to prevent their exposure to large
amounts of fluids that may destroy the tag; tag destruction
can be reduced by using tags with high rag content or even
linen tags. Use soft lead pencil or waterproof ink on these
tags; do not use ballpoint pen, nonpermanent ink, or hard
lead pencil. The most durable tag is made of soft metal, such
as copper or aluminum, and can be inscribed with ballpoint
pen, pencil, or another instrument that leaves an impression
on the tag.
Carcass
Identify each carcass with a tag fastened with wire to a
leg (Fig. 2.7). If tags are not available, use a 3- by 5-inch
card placed inside a plastic bag within the bag holding the
carcass. Information on the tag should include the name, ad¬
dress, and telephone number of the submitter, collection site,
species; whether the animal was found dead or was eutha¬
nized (indicate method); and a brief sununary of any clinical
signs. Place each tagged carcass in a separate plastic bag
and seal the bag.
Tissues and Organs
When a specimen is in a plastic bottle, jar, or tube, wrap a
piece of adhesive or masking tape entirely around the con¬
tainer and use an indelible marker to write on the tape. List
the type of animal from which the sample was taken, the
kind of tissue, and the date the sample was taken. When plas¬
tic bags are used as the first containers for tissues, they should
be labeled with the same information directly on the bag. Do
not insert tags inside containers with tissues and organs col¬
lected for microbiological or chemical analyses because the
tag or the ink on it may contaminate the specimen. When
chemically resistant tags are available, insert the tags into
containers with preservatives such as formalin or alcohol.
Specimen Preservation
Chill or freeze all specimens, depending on how long it
will take to ship to a diagnostic laboratory. Freezing reduces
the diagnostic usefulness of carcasses and tissues, but if speci¬
mens must be held for 2 or more days, freezing the speci¬
mens as soon as possible after collecting them minimizes
their decomposition. Formalin-fixed tissues should not be
frozen. See Chapter 3, Specimen Shipment, for detailed in¬
structions for packing and shipping specimens.
J. Christian Franson
(All illustrations in this chapter are by Randy Stothard Kampen, with the exception of
Figure 2.6)
Supplementary Reading
Roffe, T.J., Friend, M., and Locke, L.N., 1994, Evaluation of
causes of wildlife mortality, in Bookhout, T.A., ed., Research
and Management Techniques for Wildlife and Habitats (5):
Bethesda, Md., The Wildlife Society, p. 324-348.
Wobeser, G.A., 1997, Necropsy and sample preservation tech¬
niques, in Diseases of wild waterfowl (2nd ed): New York,
N.Y., Plenum Press, p. 237-248.
12 Field Manual of Wildlife Diseases: Birds
Chapter 3
Specimen Shipment
Specimen identification
Procedures for shipping specimens vary with different dis¬
ease diagnostic laboratories. Therefore, it is important to
contact the receiving laboratory and obtain specific shipping
instructions. This will facilitate processing of specimens when
they reach the laboratory and assure that the quality of speci¬
mens is not compromised. Time spent on field investigation,
specimen collection, and obtaining an adequate history will
be of little value if specimens become contaminated, decom¬
posed, or otherwise spoiled during shipping to the diagnos¬
tic laboratory.
There are five important consider¬
ations for proper specimen shipment:
(1) prevent cross-contamination from
specimen to specimen, (2) prevent de¬
composition of the specimen, (3) pre¬
vent leakage of fluids, (4) preserve in¬
dividual specimen identity, and (5)
properly label the package. Basic sup¬
plies needed for specimen shipment are
shown in Fig. 3.1.
Preventing Breakage and
Leakage
Isolate individual specimens from
one another by enclosing them in sepa¬
rate packages such as plastic bags. Pro¬
tect specimens from direct contact with
any coolant used (e.g., wet ice or dry
ice), and contain all materials within
the package so that leakage to the out¬
side of the shipment container is pre¬
vented if breakage occurs (e.g., blood
tubes) or materials thaw (wet ice and
frozen carcasses) due to transit delays.
Containing Specimens
Plastic bags should be strong
enough to resist being punctured by
materials contained within them and
from contact with other containers
within the package.
Styrofoam® coolers, shipped in
cardboard boxes, are useful for their in¬
sulating and shock absorbing qualities.
Styrofoam® at least l~inch thick is
preferred. When possible, select
Styrofoam® coolers that have straight
sides. Coolers that are wider at the top
than at the bottom are more likely to break during transit
than those with straight sides. Fill the space between the
outside of the Styrofoam® cooler and the cardboard box with
newspaper or other packing material to avoid cooler break¬
age (Fig. 3.2). If coolers are not available, cut sheets of
Styrofoam® insulation to fit the inside of cardboard boxes.
The cardboard box protects the Styrofoam® cooler from
being crushed during transit and serves as containment for
the entire package (Fig. 3.3). The strength of the box should
Labels
Plastic bags
Secondary containers
Specimen tubes
Metal cans with lids
Styrofoam® coolers and sheets
Insulated ice chest
Miscellaneous
Strapping tape
A
Plastic containers
!l
!l
H _ J
Chemical ice packs
Figure 3. 1 Basic specimen shipment supplies.
Specimen Shipment 13
Photos by James Runningen
Figure 3.2 Proper packing to prevent Styrofoarrf coolers
from becoming crushed during transit. Place the sealed
StyrofoanP cooler in a sturdy cardboard box. Use crumpled
newspaper or other packing material to fill all space between
the cooler and the box.
Figure 3.3 This Styrofoam'^ cooler
was not packaged in a cardboard box
for shipping.
Figure 3.4 Chemical coolants are available in (A) soft plas¬
tic, (B) hard plastic, and (C) metal containers.
be consistent with the weight of the package. Cardboard
boxes are not needed when hard plastic or metal insulated
chests are used for specimen shipment, but boxes can be used
to protect those containers from damage and to provide a
surface for attaching labels and addresses to the shipment.
Cooling and Refrigeration
Chemical ice packs (Fig. 3.4) are preferable to wet ice
because their packaging prevents them from leaking when
they thaw. Ice cubes or block ice may be used if leakage can
be prevented. This can be accomplished most easily by fill¬
ing plastic jugs such as milk, juice, and soda containers with
water and freezing them. The lids of these containers should
be taped closed to prevent them from being jarred open dur¬
ing transit.
Use dry ice to keep materials frozen, but do not use it to
ship specimens that should remain chilled because it will
freeze them. Also, the carbon dioxide given off by dry ice
can destroy some disease agents; this is of concern when
tissues, rather than whole carcasses, are being shipped. Ship¬
ment of dry ice, formalin, and alcohol is regulated and should
be cleared with the carrier before shipping.
Preparing Specimens for Shipment to the
National Wildlife Health Center (NWHC)
Other disease diagnostic laboratories may require minor
variations in shipping procedures.
1. Call the NWHC (608-270-2400) to determine the op¬
timal type and number of specimens for diagnostic proce¬
dures, how these specimens are best preserved during transit
(whether they should be chilled or frozen), and when they
should be shipped. In most cases, the NWHC requests that
specimens be shipped the same day or within 24 hours.
2. Double-bag carcasses (Fig. 3.5) and place them in a
Styrofoam® cooler lined with a plastic bag. When both fro¬
zen and fresh whole carcasses are shipped in the same con¬
tainer, the frozen carcasses can be used as a refrigerant to
keep the fresh carcasses chilled. This can be accomplished
by interspersing individually bagged frozen carcasses among
the individually bagged fresh carcasses or by placing the fresh
carcasses between two layers of frozen carcasses (Fig. 3.6).
Blood tubes and other breakable containers of uniform size
can be protected by packing them in a common plastic bag
that is sealed within a metal can or a hard plastic container
with a lid (Fig. 3.7). Pack any space around the specimen
containers within the can (side and top) with paper or some
other absorbent material to prevent jarring that could cause
breakage and to collect fluids if tubes do break. Seal the can
within a plastic bag before placing it in the Styrofoam® cooler.
3. When using chemical ice packs, intersperse them
among specimens; place within the Styrofoam* container
other types of coolants in locations that will provide maxi¬
mum cooling for all contents or, if dry ice is used, will keep
everything frozen (Fig. 3.8). Fill all empty space within the
14 Field Manual of Wildlife Diseases: Birds
Styrofoam® cooler with newspaper to prevent materials from
moving during transit. The insulating properties of newspa¬
per will also help maintain cool temperatures within the pack¬
age, and its absorbent qualities will help prevent fluid leak¬
age outside of the box or container.
4. Close the plastic bag lining the cooler and seal the lid
with strapping tape (Fig. 3.9). Tape the specimen data sheet
and history, contained in an envelope within a waterproof
plastic bag, to the top of the cooler (Fig. 3.10A).
5. Enclose the Styrofoam® cooler in a cardboard box and
secure the contents with strapping tape (Fig. 3.10B).
Figure 3.6 Frozen carcasses (white Figure 3.7 Packing sequence for blood tubes. (A) Pack blood
bags) can be used to keep fresh sped- tubes within Whirl-Pak^ or other plastic bag; (B) place bag in
mens (dark bags) chilled during short metal can or hard plastic container and pack with crumpled
transit times of 24 hours or less. Fill the newspaper or other absorbent, soft, space-filling material; and
space between the carcasses and the (C) enclose the can in a plastic bag, then seal the bag.
top of the container with newspaper to
provide additional insulation to maintain
the cold temperature.
Specimen Shipment 15
Specimen Shipment
Figure 3.8 Packing specimens for shipment when (A) ice
packs (B) wet ice, and (C) dry ice are used as cooiants. Note
that the shipping container is aiways iined with a iarge piastic
bag.
B
Figure 3.9 dosing a specimen container. (A) Secure the
iarge piastic bag containing the specimens by tying the top;
(B) dose the container iid and (C) secure the container with
severai bands of strapping tape.
Figure 3.10 Compieting the packaging process. (A) Tape
specimen data sheet and history, contained in an enveiope
within a waterproof piastic bag, to top of cooier. (B) Piace cooier
in cardboard box, secure box with severai bands of strapping
tape, and secure another copy of the specimen data sheet to
the outside of the box. if the specimens were piaced inside a
Styrofoanf cooier, then use crumpied newspaper or other
packing materiai to fiii aii spaces between the cooier and the
box.
16 Field Manual of Wildlife Diseases: Birds
Federal Shipping Regulations for
Packaging and Labeling
Your packaging and labeling of specimens must conform
to the following regulations.
The Code of Federal Regulations (CFR) states under 50
CFR Part 14 of Fish and Wildlife Regulations that contain¬
ers with wildlife specimens must bear the name and address
of the shipper and consignee, and a list of the species and
numbers of each species must be conspicuously marked on
the outside of the container. You may instead conspicuously
mark the outside of each package or container with the word
“wildlife” or the common names of the species contained
within the package. Secure an invoice or packing list that
includes the name and address of the consignee and shipper
and that accurately states the number of each species con¬
tained in the shipment to the outside of one container in the
shipment.
In addition to Fish and Wildlife Service regulations, the
interstate shipment of diagnostic specimens is subject to ap¬
plicable packaging, labeling, and shipping requirements for
disease-causing etiologic agents (42 CFR Part 72). These
regulations do not require you to identify diagnostic speci¬
mens as etiologic agents when the disease agent is not known
or is only suspected. However, all specimen packages sent
to the NWHC should be prominently labeled with the words
“DIAGNOSTIC SPECIMENS (WILDLIFE).” You can meet
packaging requirements under 42 CFR Part 72 by following
recommendations 2 through 5 above for enclosing specimens
within two containers before enclosing them within the
package.
Hazardous Materials Regulations of the Department of
Transportation apply whenever dry ice is contained within
the shipping container (49 CFR Part 172, 173, 175). Always
call the carrier ahead of time for the current shipping and
package labeling requirements. At the time of this writing,
the following must be clearly visible on containers with dry
ice: DRY ICE 9, UNI 845, weight of dry ice (kilograms), a
hazardous materials miscellaneous 9 sticker, and the com¬
plete addresses of the shipper and recipient. The dry ice
labeling should go on the side of the container, so it is vis¬
ible if something is stacked on top of it. Always include the
words “DIAGNOSTIC SPECIMENS (WILDLIFE)” on the
container. A properly labeled container is illustrated in Fig,
3.11. Label containers with permanent markers, if possible.
Commercial Carriers
Specimens should be shipped by carriers that can guaran¬
tee 24-hour delivery to the location of the diagnostic labora-
Top of box
From:
Complete return address
To:
National Wildlife Health Center
6006 Schroeder Road
Madison, Wl 53711
Diagnostic Specimens (Wildlife)
Side of box
Figure 3,11 Proper package labeling.
tory. For many locations, commercial delivery services will
pick up packages at the point of origin. When shipping ar¬
rangements have been made, contact the NWHC again and
provide the airbill number and estimated time of arrival. This
information is needed to allow prompt tracing of shipments
that may not arrive on schedule and to schedule work at the
laboratory.
J. Christian Franson
(All Illustrations in this chapter are by Randy Stothard Kampen, with the exception of
Figure 3.11)
Supplementary Reading
Code of Federal Regulations. Title 42; Part 72
Code of Federal Regulations. Title 49; Parts 172, 173, 175.
Code of Federal Regulations. Title 50; Part 14.
Specimen Shipment 17
18 Field Manual of Wildlife Diseases: Birds
Chapter 4
Disease Control Operations
Individual disease outbreaks have killed many thousands of
animals on numerous occasions. Tens of thousands of mi¬
gratory birds have died in single die-offs with as many as
1,000 birds succumbing in 1 day. The ability to successfully
combat such explosive situations is highly dependent on the
readiness of field personnel to deal with them. Because many
disease agents can spread through wildlife populations very
quickly, advance preparation is essential for preventing in¬
fected animals from spreading disease to additional species
and locations. Carefully thought-out disease contingency
plans should be developed as practical working documents
for field personnel and updated as necessary. Well-designed
plans can prove invaluable in minimizing wildlife losses and
the costs associated with disease control activities.
Although requirements for disease control operations vary
and must be tailored to each situation, all disease contingency
planning involves general concepts and basic biological in¬
formation. This chapter, which is intended to be a practical
guide, identifies the major activities and needs of disease
control operations, and relates them to disease contingency
planning.
Planning Activities
Identification of Needs
Effective planning for combating wildlife disease out¬
breaks requires an understanding of disease control opera¬
tions and the basic needs such as personnel, equipment and
supplies, permits, etc, that are associated with them (Tables
4.1 and 4.2). This information is the basis of disease contin¬
gency planning (Table 4.3; Figs. 4.1 and 4.2),
Biologicai Data Records
All disease outbreaks consist of three main components:
a susceptible host population, a disease agent interface, and
the environment in which the host and agent interact in a
manner that results in disease. Disease control involves break¬
ing the connections between these factors. Disease contin¬
gency plans expedite these efforts by providing basic infor¬
mation about the distribution and types of animal popula¬
tions in the area, animal movement patterns, any history of
disease problems on the area, and general environmental fea¬
tures. This information, along with facts gathered at the time
of a disease outbreak, provides a profile for biological
assessment and a basis for specific disease control actions.
Knowledge of the types of disease problems that have
occurred in the area, their general locations, the month and
year when they occurred, the species affected, and the gen¬
eral magnitude of losses is also of considerable value for
planning a response to a disease outbreak. Incorporate a his¬
torical summary in tabular form in the contingency plan
(Table 4,4). Animal population data are best represented by
simple graphs and charts that convey general characteristics
(Fig. 4.3); precise data are not needed. Generalized outline
maps are useful for depicting concentration and feeding
areas used by wildlife (Fig. 4.4) and major movement pat¬
terns (Fig. 4.5).
Figure 4,1 (A) Station brochures, animal lists, and other
public-use documents provide a wide variety of site-specific
background information and should be included as part of the
station’s disease contingency plan. (B) Documents contain¬
ing maps of the area indicating access points provide essen¬
tial information.
Disease Control Operations 19
Photos by James Hunningen
EXPLANATION
% Command post and headquarters administrative area
^ Staff and press briefing room
9 Parking
^ Eating area and conference room
0 Staff rest area and visitors' center
0 Equipment and supply receipt— garage
0 Decontamination areas — boathouses, transition areas, parking lots
0 Carcass disposal site and observation hill
0 Animal holding— pole barn (has cement slab and electricity)
0 Laboratory investigations — shed (has cement slab, water, electricity)
Figure 4.2 Existing work areas used for disease control operations on a wildlife management area.
20 Field Manual of Wildlife Diseases: Birds
Response Activities
Response to wildlife die-offs will vary somewhat with
the species but will always involve a set of common factors.
Waterfowl die-offs are used to illustrate specific approaches
to addressing these common factors. For large mammals, their
size and weight pose additional needs regarding carcass trans¬
port and disposal.
Problem Identification
Early detection and rapid and accurate assessment of the
causes of disease problems are essential to effective disease
control operations. This is accomplished through surveillance
of animal populations to detect sick and dead wildlife, and
the prompt submission of specimens to qualified disease
diagnostic facilities. The speed with which large numbers of
animals can become exposed to disease agents and the dif¬
ferences in control activities required for different types of
disease problems place a premium on both the speed and
accuracy of diagnostic assessments. Once a disease problem
has been identified, the following basic activities are carried
out.
Carcass Removal: Protective Clothing and Supplies
Wildlife that have died from disease are often a primary
source of the disease agent, and for most situations their car¬
casses need to be removed from the environment to prevent
disease transmission to other animals through contact with
or consumption of the carcass. Disease organisms released
from tissues and body fluids as carcasses decompose also
contaminate the environment. Some disease-causing viruses
and bacteria can survive for several weeks or longer in pond
water, mud, and soil.
Because carcass collection concentrates diseased mate¬
rial in a small area, it is essential that carcasses be handled
so that they do not release infectious agents into the environ¬
ment or jeopardize the health of personnel. Great care also
needs to be taken to prevent mechanical movement of the
disease agent from the problem area to other areas.
Personnel assigned to this task need to wear outer gar¬
ments that provide a protective barrier against direct contact
with disease organisms and that can be disinfected and
removed before personnel leave the area. Typically, these
include boots, coveralls or raingear, gloves, and a head cov¬
ering (Fig. 4.6).
Use disposable coveralls and outer gloves when possible;
the durability and cost of garments are considerations in de¬
cisions about whether or not disposable garments will be
used. Personnel should remove coveralls and outer gloves
before they leave the area, and the garments should be
destroyed if they are disposable or they should be double-
bagged before they are transported to a location where they
can be thoroughly washed before they are reused.
Dishwashing gloves, work gloves, and other types of rubber
gloves are readily available at hardware and other retail stores,
as are scrub brushes for cleaning (Fig. 4.7).
Carcass removal requires heavy-duty plastic bags or con¬
tainers. Plastic body bags used by the military are excellent
for containing wildlife carcasses. Plastic garbage cans lined
with commercially available heavy-gauge leaf and litter plas¬
tic bags are also excellent containers for transporting car¬
casses. These containers are especially useful when person¬
nel collect bird carcasses by boat (Fig. 4.8A), and for trans¬
porting carcasses in truck beds. Tie the bags shut and secure
garbage can lids when transporting these containers to car¬
cass disposal sites (Fig. 4.8B).
Depending on conditions, a variety of watercraft (Fig. 4.9)
and all-terrain vehicles (Fig. 4.10) are useful for searching
for carcasses and for transporting carcasses to collection and
disposal sites. In some instances, the expense of helicopters
may be warranted. Pickup trucks and other four-wheel ve¬
hicles are also indispensable under some field conditions.
Dogs have been used extensively in wildlife management,
and they are a valuable search tool when they are appropri¬
ately chosen and handled. Use dogs whenever possible to
locate carcasses if there is no disease risk to them. Infectious
diseases of wild North American birds do not pose a signifi¬
cant health threat to dogs. Determine disease risk on a case-
by-case basis by consulting with wildlife disease specialists.
Local retriever clubs or kennels may provide dogs.
The contingency plan should identify sources of various
equipment, whether equipment can be borrowed or rented,
and contact persons and their telephone numbers. Commonly
used supplies and equipment needed to support disease con¬
trol operations are summarized in Table 4.2.
Carcass Disposal
The primary goal of c^cass disposal is to prevent spread
of the disease agent to other animals through environmental
contamination. Because personnel will handle concentrated
amounts of infectious or highly toxic agents, this activity
requires proper training and supervision. Incineration, bury¬
ing, rendering, and composting are the four basic disposal
methods.
Incineration is generally the preferred method for dispos¬
ing of carcasses and contaminated materials associated with
wildlife disease outbreaks. However, air-quality standards
often preclude open burning, even for disease emergencies.
Consider purchasing or constructing portable incinerators
(Fig. 4.1 1) for areas with recurring disease problems if local
regulations allow using such equipment. Portable garbage
incinerators can sometimes be borrowed from State parks
and other sources. If portable incinerators are not available,
open burning with tires or other fuel or both can be used,
depending on local air pollution standards. Carcasses may
be burned either above or below ground (Fig. 4.12). It is
important to keep the fire contained and to get sufficient air
movement under the carcasses to maintain a hot fire and com¬
pletely bum the carcasses. Wood, coal, fuel oil, napalm, and
Disease Control Operations 21
NUMBER OF ANIMALS
April-August: Nesting birds and broods on Mud
and Clay Lakes and adjacent uplands.
September-mid-October: Fall migrants using
Mud and Clay Lakes.
Mid-October-January: During hunting season,
birds concentrated on Clay Lake and adjacent
marsh.
February-March: After hunting season, birds
distributed between Mud and Clay Lakes.
C
B
100
<
CO
3
o
I
Q.
o
0.
Number of geese and ducks on E. Overshoe NWR
L (5-year average)
JULY AUG SEPT OCT NOV DEC JAN FEB MAR APR MAY
MONTH
D
Peak populations of waterfowl on E. Overshoe NWR
YEAR
Figure 4.3 Examples of how to present data on seasonal and annual wildlife use of a specific area. (A) General narrative
format with map; (B) seasonal waterfowl populations by species, and total duck and goose use by (C) month and (D) year.
22 Field Manual of Wildlife Diseases: Birds
EXPLANATION
Major use areas
YZA Shorebirds and wading birds
■I Bald eagle wintering roost site
Waterfowl
1S3 Loafing areas
B Roosting areas
ED Feeding areas
- National Wildlife Refuge boundary
- • • National Wildlife Refuge Hunting Area
- - State Game Management Area
EXPLANATION
Major nfiovement patterns
Puddle duck and bay diving duck
feeding patterns
I ^ Canada goose daily feeding flights
Major use areas
Y7?\ White-tailed deer wintering area
FT! Spring migration diving duck staging
areas
Figure 4 A Example of an outline map showing concentra¬
tion and feeding areas used by wiidiife.
Figure 4.5 Example of an outline map showing major move¬
ment patterns of species.
Disease Control Operations 23
J^I^S'ife^'-' ‘' r '^1
Sti -r . »^wy)i ■:
;l»: *
I '7' '\i '
' ;~^ 'll. ,7, - Y ■ '■—
Figure 4.6 (A) Protective clothing such
as coveralls, boots, head coverings, and
gloves should be warn during carcass
cleanup activities. (B) Before leaving the
area, boots should be decontaminated
and outer clothing removed and bagged
for transportation to a location where
they can be washed before being re¬
used.
■O
Figure 4.7 (A) Examples of readily available disposable and reusable gloves for disease control operations. Dishwashing
gloves, surgical gloves, rubber work gloves, and other types can be purchased at drug and hardware stores and medical and
laboratory supply houses. (B) A wide variety of scrub brushes needed for decontaminating boots, equipment, and other sur¬
faces are also readily available from local merchants.
24 Field Manual of Wildlife Diseases: Birds
Photos by James Runningen Photo by Milton Frieni
Figure 4.8 (A) Plastic barrel being
used to transport carcasses from col¬
lection sites by airboat to disposal site.
Note use of plastic bag to line barrel.
The plastic bag containing carcasses
can be secured, removed, and placed
in a second plastic bag for further trans¬
portation if disposal site is not at the boat
docking location, thereby allowing Im¬
mediate reuse of the barrel, if the barrel
containing carcasses is to be trans¬
ported to some other location, the plas¬
tic bag should be tied closed and a cover
placed on the barrel and secured.
(B) Examples of improper transportation
of carcasses to disposal site. Note un¬
tied bags, unbagged carcasses, wooden
truck bed, and lack of tailgate. Car¬
casses and fluids contaminated with dis¬
ease organisms could easily be re¬
leased from the bags during transit. Flu¬
ids could contaminate the truck bed and
leak to the ground through the cracks
between the wooden boards. Wood ab¬
sorbs fluids and is much more difficult
to decontaminate than a nonporous sur¬
face. Also, carcasses could fail out of the
truck because there is no tailgate.
Disease Control Operations 25
Figure 4.9 Different types of (A) motorized and (B) nonmotorized watercraft are useful for carcass
collection. Note the use of plastic bags for containment of carcasses and further transportation to disposal
sites.
26 Field Manual of Wildlife Diseases: Birds
Photo by Milton Friend Photo by James Runningen
Figure 4.10 Selection of all-terrain vehicles should be
matched to local conditions. All-terrain vehicles such as these
three-wheel machines can (A) be equipped with small bas¬
kets to hold carcasses or live birds and (B) be used in water
no more than 2-feet deep. Because of safety concerns, three¬
wheeled vehicles are not recommended. (C) Large tracked
vehicles such as this equipment negotiate marshy terrain but
are not amphibious. The major advantages of this equipment
are the large capacity for carrying personnel, supplies, and
equipment and excellent visibility afforded by the height of the
vehicle. (D) Small amphibious vehicles such as this six-wheel
machine are capable of transporting two persons and are more
stable and versatile than three-wheel vehicles but are much
slower on land surfaces.
Disease Control Operations 27
p
Figure 4.11 Examples of portable
incinerators used for disease control
operations. (A) Garbage incinerator bor¬
rowed from State park to dispose of car¬
casses during Lake Andes duck plague
die-off. (B and C) Locally designed and
constructed incinerators in use during
disease control operations. All of these
are fueled with propane gas.
28 Field Manual of Wildlife Diseases: Birds
Photo by Carl Batha, Wisconsin Department of Natural Resources Photo by Milton Friend
Figure 4. 12 Examples of above-ground
and in-trench methods for incineration of car¬
casses. (A) Portable grate the width of a
pickup truck bed fashioned from metal pipes.
(B) Simple grate suspended over pit into
which carcass remains are placed for burial.
(C) Major burning pit for large-scale opera¬
tion — note surrounding area cleaned of veg¬
etation for fire protection, the size and depth
of pit, burning platform, rubber tires for fuel.—
Figure 4. 12 is continued on p. 30.
Disease Control Operations 29
Figure 4, 12— continued (D) Intensity
of heat generated by fire resuiting in the
bending of support pipes of the burning
platform and metal grate. (E) Simple but
sturdy above-ground structure of cinder
biocks and steel grates elevated enough
for fuel to be placed under the carcasses
and for air to circuiate upward. (F and
G) Highly efficient above-ground burn¬
ing platform constructed of a frame of
used grader blades, wire mat piatform,
and (H) sheet metai heat deflector
positioned at the rear of the piatform.
(i) Proper appiication of fuei oii (never
use gasoline) for carcass incineration.
Note that length of applicator prevents
flashback or wind shift from endanger¬
ing person applying fuel.
30 Field Manual of Wildlife Diseases; Birds
Photos by Milton Friend
Disease Control Operations 31
other fuels have been successfully used. Never use gasoline
because of the hazards involved. Incineration is facilitated
by stacking or piling carcasses on the burning platform, soak¬
ing them with used oil or some other fuel, and waiting about
10 to 15 minutes before igniting them. The heat generated
by large-scale carcass burning operations is intense enough
to cause metal pipes to bend (Fig. 4.1 2D). Therefore, con¬
struct a sturdy carcass support surface so that it does not
collapse into the fire.
During dry weather, burning carcasses in a pit surrounded
by a vegetation-free area is more desirable than above-ground
burning. In either situation, piling too many carcasses on the
fire at once is a common mistake; bum carcasses one layer
at a time (Fig. 4. 1 3). When cinder blocks are used to support
burning platforms, the length of the platform should be ex¬
tended to keep the blocks out of direct heat or they will soon
crumble.
When burning is not feasible or needed, burial is often a
suitable alternative. Select burial sites carefully with consid¬
eration given to ground- water circulation and drainage, and
any potential for later carcass exposure. Sprinkle lime or fuel
oil on carcasses to discourage uncovering by scavengers and
cover the carcasses with at least 3 to 4 feet of soil.
Composting is commonly used for the disposal of some
domestic animal carcasses, and it is a technique that can be
adapted to wildlife situations. The requirements for com¬
posting carcasses include an impermeable surface on which
to place composting piles, a roof or other means of control¬
ling moisture in the piles, and raw materials to mix with car¬
casses to achieve the correct carbon to nitrogen ratio for op¬
timal decomposition of carcasses (Fig. 4.14).
When the combination of animal species, cause of mor¬
tality, and local situation allow, carcasses may also be dis¬
posed of by an animal rendering plant, and in rare instances
infected wildlife may be killed and processed for food. Both
of these methods are sometimes used for domestic species
and captive-reared wildlife, but conservation laws generally
prohibit the processing of free-living wildlife (with the ex¬
ception of fish) as a commercial food source within the United
States. Judgments on the use of rendering and food process¬
ing as animal disposal methods should be made only by quali¬
fied disease control specialists.
To the extent possible, dispose of carcasses on-site to re¬
duce the risk associated with transporting contaminated ma¬
terial. Regardless of whether burning, burial, or large-scale
composting is used, earth-moving equipment is needed. The
disease contingency plan should identify how and where
bulldozers, backhoes, and similar equipment can be obtained.
Animal Relocation
It is often as necessary to deal with the live, apparently
healthy population during disease control activities as it is to
remove and dispose of animals dying from disease. Depend¬
ing on individual circumstances, consider denying animal
use of specific sites by dispersing animals from the problem
area, concentrating and holding wildlife within a specific area,
or trapping animals for sampling.
Scare devices such as propane exploders (Fig. 4. 15 A) and
cracker shells (Fig. 4.15B) may be useful for keeping wild¬
life away from a toxin or infectious agent within a specific
area. Hazing wildlife with airplanes, helicopters, airboats,
snowmobiles, and other motorized equipment has also been
successful for moving them away from disease problem
areas. Conversely, wildlife can be concentrated in an area
for euthanasia, and they can be lured to other areas by broad¬
casting and dumping large amounts of grain and other feed
to prevent their movement to problem areas, by knocking
down standing grain to make it more available to them, by
providing water through pumping operations and diverting
water flow, and by providing refuge by closing the area to
hunting and other interactions between wildlife and humans
(Fig. 4.16). Take care to assure that grain used for attracting
wildlife is not moldy and does not contain dangerous con¬
centrations of my cotoxins.
Figure 4. 13 Examples of (A) correct and (B) incorrect layering of carcasses for burning. Carcasses must be burned one layer
at a time to prevent charred outer carcasses from insulating inner carcasses from incineration. (Illustration by Randy Stothard
Kampen)
32 Field Manual of Wildlife Diseases: Birds
Figure 4.14 Example of a simple composting bin for waterfowl carcasses. Litter (bedded
manure from poultry houses is a good source), straw, and carcasses are added propor¬
tionally to achieve the appropriate moisture content and carbon to nitrogen ratio. (Modified
from Rynk, 1992.)
Food and water are also helpful in trapping wildlife for
assessing disease control activities. When birds have been
lured to a site, they may be captured by such means as drugs
incorporated within feed, rocket nets, drop nets, walk-in and
swim-in traps, or other means of preventing escape (Fig.
4.17).
A timely response to disease outbreaks can be facilitated
if such factors as need for special permits, area closures,
possible involvement of endangered species, and water pur¬
chase can be anticipated and addressed before an urgent situ¬
ation arises.
Because of the potential complexity of biological inter¬
actions in animal relocation, field managers should seek the
advice of disease control specialists whenever possible be¬
fore taking independent action. As a general rule, animal dis¬
persal is not recommended when infectious disease is in¬
volved unless it can be assured that the population being dis¬
persed will not infect other wildlife. Also, it is important that
water manipulation not produce conditions favorable to de¬
velopment of botulism or other disease problems.
Disinfection
The purpose of disinfection is to prevent the mechanical
transmission of disease agents from one location to another
by people, equipment, and supplies. Some viruses, bacteria,
and other infectious agents have considerable environmen¬
tal persistence. Disinfection of the local environment involved
in a disease outbreak may be required to prevent recurrence
of the disease when the site is used by other animals. Disin¬
fection of a disease outbreak site should always be done
under the direct guidance of disease control specialists.
Wash thoroughly the clothing worn during disease con¬
trol (coveralls and clothes worn under protective raingear)
before it is used again. Personnel should shower and sham¬
poo their hair before leaving the site, if possible, but always
before they go to other wildlife areas. Disinfect boots before
entering vehicles when in contaminated areas, and disinfect
all equipment to the extent possible before it is moved from
the area (Fig. 4.18A and B). Give special attention to the
underside of vehicles (Fig. 4. 1 8C and D). Put motor vehicles
through a car wash before moving them to other areas, and
wash and clean boats and all-terrain vehicles before they leave
the area. Large volume tanks and pumps that can be oper¬
ated from mobile units such as trucks (Fig. 4.19) and boats
are especially useful for holding and dispensing disinfec¬
tant.
Disinfection procedures require a suitable disinfectant,
containers for that disinfectant once it has been diluted to
appropriate strength, and a way of applying the disinfectant.
Commercial disinfectants are available from farm supply
stores and veterinarians. Refuge managers and other field
managers should consider keeping a supply of disinfectant
for general use. Chlorine bleach is a highly suitable disin¬
fectant and it is available at most grocery stores. For general
Disease Control Operations 33
Figure 4. 15 Wildlife can be discouraged from use of areas
by (A) propane exploders that function by the ignition of pro¬
pane gas within the “cannon” due to the striking of a fiint at a
timed interval. With the exception of placing the cannon and
maintaining a fuei supply, this activity does not require the
presence of personnel. (B) Manual firing of cracker shelis has
also been used successfully to discourage wiidlife use of
areas. These fireworks-like shelis should only be fired through
a break-open type shotgun so that the barrel can be checked
between shots to assure that there are no obstructions re¬
maining in the barrels. These shells should not be used where
they can fall into dry vegetation because of fire hazard.
Figure 4. 16 Closure of areas is often needed to assist dis¬
ease controi operations. (A) Sign used to close Lake Andes
National Wildlife Refuge during the duck plague die-off. (B)
Sign used to delineate refuge area so that bird disturbance
and movement was minimized during another South Dakota
disease control operation.
use, dilute one part chlorine bleach with 10 parts water. Use
stronger concentrations of one part bleach to five parts water
for disinfecting heavily contaminated areas.
Stiff bristle brushes, buckets, and containers that can be
used for foot baths and pressure or hand sprayers that can be
used to dispense the disinfectant are also needed. The sta¬
tion contingency disease plan should identify readily avail¬
able sources of these supplies and equipment.
When the disease problem involves an infectious agent,
personnel handling contaminated materials should refrain
from working with similar species or those susceptible to
the disease for at least 7 days following completion of their
disease control activities. For example, a field manager in¬
volved in an intensive avian cholera disease control opera¬
tion on Monday should not band waterfowl in that refuge or
elsewhere until Tuesday of the next week.
Personnel
Labor-intensive operations such as carcass removal and
disposal sometimes require more personnel than are usually
employed on an area. In some instances, specialized help
such as low level aircraft flights for surveillance may be
needed. The use of nonstation personnel for routine opera¬
tions has a potential educational value. For example, the use
of local sportsmen clubs to help with carcass collections
during a major lead poisoning die-off has been highly effec¬
tive in changing negative attitudes towards nontoxic shot use.
Sportsmen clubs; retriever clubs; biology and wildlife
classes at local universities and colleges; local chapters of
conservation organizations such as the Audubon Society; the
active military and National Guard, who also may provide
valuable technical assistance; and similar groups have all
provided volunteer assistance in combating disease problems
34 Field Manual of Wildlife Diseases: Birds
Figure 4.17 Various types of capture devices are use¬
ful for disease operations. (A) Rocket net being fired
over Canada geese. (B) Snow geese captured by can¬
non nets. (C) Constructing a funnel trap to capture birds
in a zoological park.— Figure 4. 17 is continued on p. 36.
Disease Control Operations 35
Figure 4, 17— continued (D) Capturing birds
within a funnel trap. (E) Capturing flightless
Canada geese in a drive trap. (F) Capturing
waterfowl in a large, baited funnel trap. (G)
Using drugged grain to capture birds in resi¬
dential situations. When drugs are used,
maintain close surveillance of the situation
so that animals that become drugged, such
as the bird (H) lying on its back, can be
promptly collected before they are seized by
other animals or drown if they venture into
the water before the drug takes effect.
36 Field Manual of Wildlife Diseases: Birds
Photos by Milton Friend
p
Figure 4. 18 Equipment and personnel should be disinfected
to the extent possible before leaving disease operation areas.
(A) Initial disinfection procedures should take place well within
the contaminated area. (B) Boots and other items In contact
with the ground should receive a second application of disin¬
fectant at the point where entry Is made Into the “clean area"
as Is being done at the location where the specimen chest Is
being transferred. (C and D) Various types of spray units can
be used to apply disinfectant to the underside of vehicles. Tires
and wheel wells are the primary areas of concern as they
may contain contaminated soil or animal fecal material from
the disease area.
38 Field Manual of Wildlife Diseases; Birds
Photo by Milton Friend Photo by J. Christian Franson Photo by Milton Friend Photo by Milton Friend
Figure 4.19 (A) Portable tank and pump mounted on a truck bed for dispersing disinfectant during
duck plague control operation and (B) application of that disinfectant to a structure used to house birds.
The long length of hose on this unit allowed all areas of major bird use to be reached from service and
perimeter roads.
Disease Control Operations 39
at various times and places. Sound judgment must be exer¬
cised in the selection and utilization of volunteers because
of legal liability in case of an accident. Contingency plans
should list groups and organizations and contact persons for
each group, their telephone numbers, and an approximation
of the work force and times of its availability (e.g., week¬
ends only or Wednesday only). For technical assistance, list
the specific type of personnel needed, such as bulldozer op¬
erator or helicopter pilot.
In addition to preparing a station contingency plan, wild¬
life personnel should become familiar with the other phases
of disease control operations. Table 4. 1 provides a descrip¬
tive outline of these phases. Especially relevant to field man¬
agers are the equipment and supply needs identified under
the Disease Response Section of Table 4.3.
Response Modifications
Disease control operations can be seriously undermined
without current assessment of wildlife morbidity and mor¬
tality and the cause of disease problems. When infectious or
highly toxic agents are involved, early detection of disease
problems is critical to preventing the problem from becom¬
ing widespread. Also, failure to accurately assess the cause
of the die-off can result in control actions actually contrib¬
uting to the magnitude of losses and spread of the problem.
Different types of disease problems require different types
of response. Do not assume that the current die-off is due to
the same cause as previous die-offs that have occurred on
the area or that only one disease agent is responsible. It is
not uncommon for two or more causes of wildlife mortality
to occur simultaneously in an area. Control of these differ¬
ent diseases may require opposite types of actions, thereby
requiring that a more comprehensive strategy be developed
for the disease control operation.
Refuge managers and other field biologists greatly influ¬
ence the effectiveness of disease control operations by their
responsiveness, knowledge of the local situation, how well
they are prepared, the flexibility they maintain, their resource¬
fulness, and when possible, their ability to obtain appropri¬
ate technical assistance and training for combating disease
problems. Timely and properly carried-out disease control
activities can significantly reduce the magnitude of wildlife
losses that might otherwise occur. When carrying out con¬
trol activities, always consider the safety of the personnel
involved.
Milton Friend and J. Christian Franson
Supplementary Reading
Friend, M., 1995, Disease considerations for waterfowl managers
in Whitman, W. R., and others, eds.. Waterfowl Habitat
Restoration Enhancement and Management in the Atlantic
Flyway (3): Dover, Del., Delaware Department of Natural
Resources and Environmental Control, p. J24-J117.
Roffe, T.J., Friend, M., Locke, L.N., Evaluation of causes of
wildlife mortality, in Bookout, T. A., editor, 1994, Research
and management techniques for wildlife and habitats. Fifth
ed.,: Bethesda, Md., The Wildlife Society, p. 324-348
Rynk, R., ed., 1992, On-farm composting handbook: Ithaca, N.Y.,
Northeast Regional Agricultural Engineering Service, 186 p.
Wobeser, G. A., 1994, Investigation and management of disease in
wild animals: New York, N.Y., Plenum Press, 265 p.
40 Field Manual of Wildlife Diseases: Birds
Table 4. 1 Outline of disease control operations.
I. Planning
A. Identify needs
1 . Sources of additional personnel to help during disease emergencies. Potentially, these include
a. State and Federal agencies
b. Active military and National Guard
c. Private conservation agencies
d. Local sporting clubs
e. Local universities
2. Sources and availability of equipment and supplies for disease control operations (Appendix C)
3. Special needs
a. Burning permits
b. Endangered species consultations
c. Lodging and meal facilities for work crews
d. Ability to attract and hold wildlife in site-specific areas by providing food, water, refuge, or other
means
e. Ability to deny wildlife use of specific areas by scaring devices and other means
f. Ability to capture wildlife for sampling, immunization, or other needs
B. Record biological information
1 . Daily and seasonal wildlife movement patterns within the general area
2. Migration patterns and population peaks for major and endangered species
3. Past history of diseases
C. Prepare contingency plan (See Tables 4.2 and 4.3.)
II. Initial Response
A. Identify problems
1 . Obtain diagnosis by submitting carcasses to a qualified diagnostic laboratory as soon as mortality or
morbidity is evident. (See Chapters 3 and 4 for shipping procedures.)
2. Conduct field investigation to determine extent of problem (i.e., species, number of wildlife, and geo¬
graphic area involved).
3. Identify special biological, political, or physical considerations associated with problem. Before
proceeding further with II. B and C., seek the advice of a specialist.
B. Establish control of area
1. Close affected area, when warranted, to all but authorized personnel.
2. Identify special work areas for disease control activities.
a. Carcass disposal sites
b. Laboratory investigations area
c. Briefing area for news media and staff
d. Vehicle parking
e. Assembly areas for arriving workers
f. Command post
3. Initiate carcass cleanup, but do not dispose of carcasses without guidance from disease control
specialists.
Disease Control Operations 41
Table 4.1
Outline of disease controi operations (continued).
C. Communications
Notify appropriate agency and nonagency personnel of die-off.
III. Disease Control
A. Response
1 . Disease control actions are dictated by the type of disease, environmental factors, species involved,
and other circumstances. Typically, actions associated with major die-offs require:
a. Bringing personnel, equipment, and supplies on-site
b. Organizing workforce, briefing workers about the problem, and assigning duties
c. Carcass pickup and disposal
d. Monitoring cause of mortality to detect changes in the cause of the problem (die-offs often involve
more than a single cause and different control actions may be required for these different causes)
e. Decontamination of personnel and equipment
f. News media briefing sessions and “show-me” trips^
B. Management
1 . Disease management activities often involve:
a. Population manipulation such as removal, controlled movement including relocation and local
concentration of wildlife populations, and population dispersal
b. Habitat manipulation to prevent, attract, or maintain wildlife use of an area
2. Decontamination of the infected environment, such as:
a. Chemical treatment of land, water, and structures
b. Vegetation and water removal (desiccation) to allow air and sunlight (ultraviolet) to destroy micro¬
organisms
C. Controlled burning to remove vegetation and dispose of mechanical structures
IV. Surveillance
A. Monitoring
After disease control operations have ended, the area should be kept under surveillance for 10 to 30 days
to watch for additional flareups.
B. Investigations
This stage is also an appropriate time to conduct followup investigations of factors that helped cause and
sustain the problem, and to carry out wildlife and environmental sampling to discern disease
exposure patterns and environmental reservoirs of disease agents.
V. Analyses
Each disease control operation provides a learning experience. It is important to the success of future
operations to evaluate what was done, the degree of success achieved, problems encountered, and what
should have been done differently.
' Media briefing sessions and “show-me” trips should be conducted by personnel with comprehensive know¬
ledge of the situation.
42 Field Manual of Wildlife Diseases: Birds
Table 4.2 Equipment and supplies used in disease control operations.
Activity
Equipment and supplies
A. Carcass Collection
1 . Transportation of personnei a. All-terrain and four-wheel vehicles, snowmobiles
b. Airboats, canoes, other boats
c. Helicopter
d. Waders, snowshoes
2. Transportation of carcasses a. Large, heavy-duty plastic bags
b. Plastic trash cans with lids
c. Sleighs and trailers
d. Trucks, boats
e. Strapping tape and other means of securing closure of con¬
tainers
B. Carcass Disposal
1 . Burial a. Earth-moving equipment for digging trenches or pits (bull¬
dozer, backhoe)
b. Shovels
c. Lime or fuel oil to spread on carcasses
d. Any applicable permits
2. Incineration a. Portable incinerators and fuel
b. Local permanent incinerator
c. Earth-moving equipment for digging trenches or pits
(bulldozer, backhoe)
d. Burning permits
e. Shovels
f. Metal grates and cinder blocks for building burning platforms
g. Sheet metal or metal roofing for heat reflectors
h. Fuel for burning carcasses (wood, coal, rubber tires, fuel oil,
napalm)
I. Fire suppression equipment
3. Composting a. Composting bin made of pressure-treated lumber
b. Straw and manure to alternate with layers of dead birds
c. Trucks to transport carcasses, straw, and manure
C. Sanitation Procedures
1 . Decontamination of environment a. Chemical disinfectants and structures
b. Pumps and suction apparatus for drainage of water areas
c. Buckets, brushes
d. Spray appiication by aircraft, power systems mounted in
trucks and boats, and hand-carried spray units
2. Protection of personnel and prevention a. Raingear, coveralls, rubber gloves, rubber foot gear, hats
of mechanical movement of disease b. Spray units and chemical disinfectants
agents to secondary locations by peopie c. Plastic bags for transportation of field clothes to laundry
and equipment d. Brushes, buckets
e. Disposabie gloves, hats, coveralls, and foot coverings
Disease Control Operations 43
Table 4.2 Equipment and supplies used in disease control operations (continued).
Activity
Equipment and supplies
D. Field Communications
1 . Field activities
a. Portable radios or cellular telephones for communication
between field personnel
b. Radios in vehicles for communication between field units and
between units and command post
2. Information activities
a. Word processor or typewriter for preparing briefing documents
b. Maps, acetate, and other supplies for overlays depicting die¬
off and control activity information
c. Telephone lines for communication with others
d. Transportation for news media “show-me” trips
E. Surveillance and Observation
1 . Field activities
a. Aircraft and pilots certified for low-level flights (500 feet and
below) for monitoring wildlife populations and
environmental conditions
b. Binoculars and spotting scopes
2. Office activities
a. Maps, acetate, and other supplies for tracking the progress of
events and wildlife populations associated with die-off
b. Telephone for contacting others to trace movement of migrant
bird populations that might enter problem area or that have
departed problem area
F. Wildlife Population and Habitat Manipulation
1. Denying wildlife use of an area a. Aircraft, boats, snowmobiles, and other motorized means of
hazing wildlife populations
b. Propane exploders
c. Cracker shells, break-open shotguns, and protective face
shield
d. Audio systems and other scare devices
e. Pumps for draining water or adding water to areas
2. Concentration and maintenance of
wildlife in a specific area
a. Grain and other sources of food
b. Pumps and water to provide habitat
c. “No Hunting” and “Area Closed” signs to provide temporary
refuge area
G. Wildlife Sampling and Monitoring
1 . Wildlife capture a. Cannon nets and other capture equipment
b. Grain and other baits to lure wildlife to capture site
2. Wildlife marking
a. Visible marking devices such as paint, neck collars, and other
devices
b. Permanent marking devices such as leg bands and ear tags
(see Bookhout, 1 994)
c. Temporary marking devices such as radio transmitters
44 Field Manual of Wildlife Diseases: Birds
Table 4.3 Station disease contingency plan.
I. Introduction
A. Size, configuration, and other important characteristics of station area conveyed with heip of tabies,
maps, photographs, station brochures, pubiic use maps, and similar documents
B. Record of previous disease outbreaks, including nature of disease, species involved, magnitude of die-off,
and season and year (Table 4.4)
II. Disease Surveillance
A. Brief outline of current surveillance activities on station and adjacent areas — State, Federal, and private
B. Identify disease reporting and notification procedures (names, titles, organization, and telephone numbers
of persons to be contacted)
III. Disease Response
A. Logistical considerations
1 . Personnel sources (telephone numbers, addresses, names of contact persons)
a. Local, State, and Federal agencies (military, university)
b. Sporting clubs and volunteers
2. Equipment (types and numbers on-site, and sources off-site)
a. Vehicles (conventional and all-terrain)
b. Aircraft (fixed-wing and rotary)
c. Earth-moving equipment (backhoe, bulldozer)
d. Pumps (for flooding or draining marshes)
e. Boats (motor, seif-propelied, air boats)
f. Radios (portable and fixed); during nonfire seasons the
National Interagency Fire Center
3905 Vista Avenue
Boise, Idaho 83704
(208) 389-2458
is a potential source for obtaining assistance for very large communication needs
g. Incinerators
h. Composting bins
i. Decontamination units (sprayers)
j. Scaring devices (propane exploders, sirens)
k. Freezers
l. Portable toilets (construction-site type)
3. Supply sources (Identify sources, addresses, and telephone numbers of local or closest sources.)
a. Disinfectants and chemicals
b. Plastic bags
c. Fuel for carcass burning
d. Field clothes (gloves, rainwear, coveralls, boots)
e. Plastic trash barrels, tubs, scrub brushes
f. Scaring devices (cracker shells, fireworks): provide contact telephone number and address for local
animal damage control office
g. Dry ice and liquid nitrogen
h. Grain and other wildlife foods
i. Nearest shipping address for air and ground receipt of goods and supplies
Disease Control Operations 45
Table 4.3 Station disease contingency pian (continued).
4. Lodging for temporary personnel assigned to disease control operation
5. Food
a. On-site capabilities
b. Off-site capabilities (Give consideration to early and late hours.)
6. Identify working areas (Diagrams are sufficient; limited narrative may also be required; Fig. 4.2.)
a. Clean areas
1 . Command post (must have adequate telephones)
2. News media briefing room
3. Parking
4. Eating areas
5. Staff assembly and rest areas
6. Equipment and supply receipt
7. Other
b. Transition areas
1 . Decontamination of personnel
2. Decontamination of equipment
c. Contaminated areas
1 . Carcass disposal
2. Laboratory investigations
3. Animal holding
B. Biological considerations (Provide data in charts, figures, photographs, maps, tabies.)
1 . Species and population data
a. Major species (Identify by season of presence, relative abundance, and peak population periods.)
2. Wildlife movement patterns (Figs. 4.3 through 4.5)
a. Daily
b. Seasonal
c. Production and dispersal patterns
3. Weather patterns
a. Freeze-up and ice-out periods
b. Major periods of precipitation and drought
c. Other (temperature profiles, major periods of haze, fog, and high winds)
4. Habitat and population manipulation potential
a. Methods (water manipulation capability, feeding)
b. Anticipated population response to habitat (movement, concentration, dispersal)
C. Communications (Provide lists of principal local and regional contact personnel and telephone numbers.)
1 . State agencies
a. Conservation
b. Agriculture
c. Health department
d. University diagnostic laboratories
46 Field Manual of Wildlife Diseases: Birds
Table 4.3 Station disease contingency pian (continued).
2. Federal agencies
a. Environmental Protection Agency
b. U.S. Department of Agriculture
c. U.S. Public Health Service
3. Other organizations
a. Cooperating organizations (e.g., area representatives of Audubon Society, National Wildlife
Federation, Ducks Unlimited)
b. Local sporting clubs
c. Private wildlife area managers
d. Local game breeder organizations
e. Local domestic animal husbandry and production operations
4. Media
a. Television
b. Radio
c. Newspapers
IV. Supplemental Information
A. Location of nearby laboratories (hospitais, universities, county and State facilities)
B. Federal and State permit status for biological collections
C. Burning permits
D. Regulatory requirements
E. Background information (e.g., water sources, water-quality data, potential sources of disease
transmission between wildlife and domestic animal concentrations)
F. Identification and location of adjacent or nearby wildlife refuges, management areas, and private reserves
G. Identification of unusual or politically sensitive aspects of area
Disease Control Operations 47
Table 4.4 Example of a disease outbreak summary for a wildlife management areaK /— , no data available]
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48 Field Manual of Wildlife Diseases: Birds
Chapter 5
Euthanasia
Background
Euthanasia means to cause humane death. Some current
euthanasia techniques may become unacceptable over time
and be replaced by new techniques as more data are gath¬
ered and evaluated. The following information and recom¬
mendations are based largely on the 1 993 report of the Ameri-
can Veterinary Medical Association (AVMA) Panel on
Euthanasia. The recommendations in the panel report were
intended to serve as guidelines, and they require the use of
professional judgement for specific situations. Ultimately, it
is the responsibility of those persons carrying out euthanasia
to assure that it is done in the most humane manner possible.
There is no perfect euthanasia technique appropriate to
all situations. What is sought in each instance is immediate
insensitivity of the animal to pain as a result of depression of
the central nervous system (brain and spinal cord). The
AVMA panel in its evaluation considered the following to
be important factors to consider when selecting a euthanasia
method:
Considerations for seiecting a euthanasia method
• Does the method cause the animal to lose conscious¬
ness and die without causing the animal pain, distress,
anxiety, or apprehension?
• How much time does the method require to induce
unconsciousness?
• Is the method reliable?
• Does the method put personnel at risk of injury or
health problems?
• Is the method irreversible?
• Is the method compatible with the purpose of eutha¬
nasia?
• Will the method cause distress and anxiety among
observers and personnel?
• Does the method interfere with or detract from the
subsequent evaluation, examination, and use of tis¬
sue?
: • Are drugs required by the method available? Can the
drugs be abused by humans?
• Is the method appropriate for the animal age and spe¬
cies?
• Is the equipment required by the method in proper
working order?
• Is the method cost-effective?
Methods of euthanasia are physical or chemical. Physical
methods of euthanasia include cervical dislocation, decapi¬
tation, stunning and removal of blood, and gunshot. Chemi¬
cal methods of euthanasia involve introducing a toxic agent
into the body by injection or inhalation. After completing
euthanasia, be certain that specimens being collected are
properly identified, preserved, and packaged for transporta¬
tion to the diagnostic laboratory (see Chapter 2, Specimen
Collection and Preservation, and Chapter 3, Specimen Ship¬
ment). Be sure to indicate the euthanasia technique used.
Physical Euthanasia
Cervical Dislocation
Cervical dislocation can be used without any special
equipment to euthanize small birds and ducks. The disloca¬
tion must take place at the base of the brain, or within the
upper one-third of the neck (the cervical spine). Grasp the
base of the bird’s skull in one hand and its body, usually at
the base of the neck, in your other hand. Pulling rapidly and
firmly in opposite directions will separate the spinal cord
(Fig. 5.1). Cervical dislocation can be used for larger birds,
like geese, by separating the upper cervical spine with an
emasculatome, which is available from veterinary supply
Figure 5.1 Cervical dislocation procedures. The brain can
be separated from the spine in small- to medium-sized ani¬
mals by grasping the animal at the base of the skull with one
hand, at the base of the neck with the other, and pulling rap¬
idly and firmly in opposite directions with a strong snapping
action.
Euthanasia 49
stores. As with all methods, learn how to properly use this
instrument before applying it to a live animal.
Cervical dislocation may upset the casual observer be¬
cause animals, especially birds, convulse for several seconds
to minutes after death. These movements are due to spinal
reflexes and the animals do not feel pain. This technique is
effective, rapid, inexpensive, and only minimally affects di¬
agnostic testing.
Decapitation
Severing the head from the neck is an effective method of
euthanasia for small mammals and any size bird, but it is
often used for larger waterfowl. Use a knife, machete, hatchet,
or bolt cutters to ensure that the spinal cord, encased in the
cervical spine, is severed. The same convulsions seen after
cervical dislocation will follow decapitation. This technique
has similar attributes as cervical dislocation. However, take
care to prevent injuries to personnel resulting from the use
of the sharp implements, and to prevent exposing personnel
to toxic or infectious agents that may be in the blood.
Stunning and Exsanguination (Removai of Blood)
This method requires striking the center of the skull to
render the animal unconscious, followed by severing the ma¬
jor blood vessels in the neck, and allowing the animal to
bleed out. Do not use this technique if the brain is required
for diagnostic tests.
Gunshot
Shooting animals in the head, or the neck if the brain is
needed for diagnostic purposes, with a small caliber rifle can
be used as a method of euthanasia. Training and experience
are required to assure a humane death, and also to reduce the
human safety hazards.
Chemical Euthanasia
Extreme caution is required for the use of chemical eu¬
thanasia, because of the potential hazards for humans. These
procedures should be carried out only by trained individuals
who are properly authorized to use the appropriate chemi¬
cals.
Inhalant Anesthetics
Several inhalant anesthetics have been used for wildlife
euthanasia. Halothane is often the inhalant selected because
it rapidly induces unconsciousness. Enflurane also rapidly
induces unconsciousness, but seizures under deep anesthe¬
sia from enflurane are more common than from halothane.
Methoxyflurane vaporizes slowly and, therefore, has a longer
anesthetic induction time, which can cause the bird to be¬
come agitated. Isoflurane has a rapid induction time, but its
odor can cause the animal to hold its breath, thereby delay¬
ing unconsciousness. Nitrous oxide has a low potency and is
available only in gas form; other anesthetics are purchased
as a liquid, and they vaporize at room temperature and nor¬
mal air pressure. Nitrous oxide can be used in combination
with other inhalants to speed anesthesia, but it should not be
used alone because animals often become agitated and dis¬
tressed before they lose unconsciousness.
To administer an inhalant anesthetic for euthanasia of an
individual bird, prepare a cone (from a syringe case or other
plastic material) that will fit snugly when it is placed over
the beak and nares (Fig. 5.2). Pour a small amount of the
anesthetic agent on a piece of cotton, tissue, or cloth, and
place it in the narrow part of the cone. Restrain the bird; put
the open end of the cone over the beak and nares, and con¬
tinue restraining the bird until it becomes unconscious. Re¬
straint can then be discontinued, but keep the cone in place
for several minutes before checking to assure that the bird is
Figure 5,2 A cone prepared from an empty syringe case
can be used for euthanasia. Tape a piece of latex glove over
the open end of the cone, and cut a slit in the latex so that the
bill and nares fit through it Place the anesthetic agent on a
piece of cotton in the end of the cone.
dead. Alternatively, place an individual bird, or several small
birds, in a cage or crate; cover it with plastic or place the
cage in a covered plastic barrel. Place the cotton, tissue, or
cloth soaked with anesthetic agent inside the chamber with
the birds and tie or otherwise seal the plastic to prevent the
vaporized agent from escaping (Fig. 5.3). Cold temperatures
will decrease the rate at which the liquid becomes gas. Small
mammals can be euthanized by similar procedures.
A animal exposed to anesthetic gas may pass through an
“excitation phase” before it becomes unconscious; it may
vocalize and appear to struggle for a short time. This behav¬
ior may be distressing to the casual observer and it can be
dangerous for the handler, depending on the species. It is
important to assure that the animal is dead, and not just un¬
conscious, before shipment, necropsy, or disposition. After
removing the animal from the gas environment, it may wake
up quickly, with little warning. Remember this when work¬
ing with raptors, carnivores, and other biting animals.
Because all of these gases constitute a human health haz¬
ard, including the potential to cause spontaneous abortion
and congenital abnormalities, the workplace must be well-
ventilated.
50 Field Manual of Wildlife Diseases: Birds
Figure 5.3 Use of cage enclosed with plastic for euthanasia of birds. (A) Anesthetic agent placed on a piece of cloth under the
cage. (B) Evaporation of dry ice. (C) Direct application of carbon dioxide gas. Because this gas is heavier than air, a deep layer
of gas must be built up so that the animals being euthanized cannot get above the gas. The chamber containing the animals
must not be airtight or gas buildup may result in an explosion. Openings should be at the top of the chamber.
Toxic Gas
Toxic gases such as carbon monoxide (CO) or carbon di¬
oxide (CO^) may be useful when many small birds or ani¬
mals must be killed. Keep in mind that, even at concentra¬
tions of less than 1 percent, carbon monoxide is lethal and
represents a substantial human safety hazard because it is
highly toxic and difficult to detect. In concentrations exceed¬
ing 10 percent, carbon dioxide can be flammable and explo¬
sive. Work with this gas, as with anesthetic gases, must be
conducted in an open area away from electrical equipment.
Carbon monoxide and carbon dioxide may be purchased
as compressed gases in cylinders. Dry ice can also be used
as a source of carbon dioxide. If dry ice is used, protect ani¬
mals from contact with it. Cages covered with plastic bags
(Fig. 5.3) or plastic garbage cans can be used as killing cham¬
bers, but the cages must be vented to allow displacement of
air within the chamber by the toxic gas. Leave the animals in
the chamber until breathing and heartbeat have ceased.
Lethal Injection
To administer lethal injections, personnel must be trained
in injection techniques and proper doses as well as in the
safe handling and disposal of needles, syringes, and drugs.
Federal drug regulations make the use of these agents, ex¬
cept by licensed veterinarians, largely impractical. Lethal
injections can be used for any animal that can be given an
intravenous injection, but they are probably most useful for
mammals and large birds, such as geese.
Sleepaway® (made by Ft. Dodge Laboratories, Inc., Ft.
Dodge, Iowa) and Beuthanasia - D Special® (made by Burns-
Biotic Laboratories, Inc. Omaha, Neb.) are concentrated bar¬
biturate solutions plus additives. The solutions are inexpen¬
sive, but, due to the potential for human abuse, require
licensing by the Federal Drug Enforcement Administration
(DEA) for purchase, use, and storage. Considerable record¬
keeping of use of the drug is required by the DEA.
Lethal injections may not be appropriate in certain in¬
stances because drug residues interfere with some tests.
Check first with the diagnostic laboratory to see if the pro¬
posed euthanasia technique is compatible with the testing to
be performed.
The need for individual handling and injection of each
animal generally precludes using this technique for euthana¬
sia of more than a few birds or animals per event. Proper
disposal of carcasses is needed to prevent secondary poison¬
ing of scavenger species in situations where more birds or
animals are euthanized than are needed for diagnostic test¬
ing.
J. Christian Franson
(Modified from an earlier chapter by Patricia A. Gullet)
Supplementary Reading
Andrews, E.J., Chairman, 1993 Report of the American Veterinary
Medical Association panel on euthanasia, 15 January 1993;
Journal of American Veterinary Medical Association 202:229-
249.
Euthanasia 51
52 Field Manual of Wildlife Diseases: Birds
Chapter 6
Guidelines for Proper Care and Use of
Wildiife in Fieid Research
Prologue
Public attitudes towards animals continue to change over
time. These changes apply to wildlife along with other spe¬
cies, and in recent years, attitudes have been increasingly
oriented toward assuring that all species receive proper care
whenever human interactions are involved. Guidance regard¬
ing the application of euthanasia is provided in the previous
chapter. This chapter provides basic guidelines for the proper
use of wildlife in field investigations. We believe this previ¬
ously published information from The Wildlife Society is
sufficiently important to include in this field manual. The
Wildlife Society has been kind enough to grant permission
for this reproduction. The scope of this chapter extends to
all wildlife, and the application of this material extends be¬
yond research to all wildlife investigations. This chapter is
reproduced, with the addition of illustrations and minor modi¬
fications, as it appeared in Research and Management Tech¬
niques for Wildlife and Habitats (Bookhout, 1994), and, thus,
it deviates from the format for the rest of Volume I.
Introduction
Philosophy
Scientists do not operate in a vacuum, but rather in an
arena with responsibilities to the organisms they study and
to society. Professional scientists must consider the effects
of their activities on the organisms under study, on the valid¬
ity of study results, and on the use of these organisms by
other segments of society. The Wildlife Society recognizes
these relationships and supports the sound application of re¬
sponsible methods for the conduct of animal research in all
field and laboratory investigations. This position reflects our
ethical and moral concerns regarding human interactions with
each other and with other species, and recognizes the scien¬
tific benefits of investigations that are not compromised by
the manner in which animals are handled or maintained.
These concerns are the foundation for our philosophy that
responsible methods of animal investigations must include
all animal species. Wildlife professionals are urged to apply
high standards of animal care and maintenance, and respon¬
sible methods of experimental procedures, in conducting each
animal investigation.
Purpose
These guidelines are intended for field research involv¬
ing wild animals. The variety of wild vertebrates investigated
and of conditions encountered precludes provision of spe¬
cific information applicable to each situation. Lists of useful
references for those seeking more specific information are
provided in the Appendices.
Background
The Animal Welfare Act (7 U.S.C. 2131, and following)
was enacted on 23 December 1985, with amendments in¬
cluding Parts 1, 2, and 3 (9CFR); Fed. Register 4(168)
3611236163, effective 30 October 1989. The Act established
definitions of terms (Part 1) used in the regulations (Part 2)
and standards (Part 3) for the humane handling, care, treat¬
ment, and transportation of regulated animals used for re¬
search or exhibition purposes, sold as pets, or transported in
commerce. Excluded from the provisions of the Act are cold¬
blooded vertebrates, birds, rats (Rattus) and mice (Mus) bred
for use in research, horses and other farm animals used or
intended for use as food and fiber, and livestock and poultry
used or intended for use in improving animal nutrition, breed¬
ing, management, or production efficiency, or for improving
the quality of food or fiber. Also excluded are field studies
as defined by the Act, i.e., “any study conducted on free-
living wild animals in their natural habitat, which does not
involve an invasive procedure, and which does not harm or
materially alter the behavior of the animals under study.”
Collection of blood samples, ear-notching, branding, and
collection of routine weight and measurement data are ex¬
amples of exempted activities.
Exclusion of animal species under the Act removes re¬
porting requirements and reduces oversight by the U.S. De¬
partment of Agriculture, but does not negate coverage of these
species under guidelines established by other agencies. Thus,
fish, amphibians, reptiles, birds, and mammals are covered
by the National Science Foundation (NSF) and the National
Institutes of Health (NIH) guidelines. This coverage is ex¬
tended to research grants funded by these agencies and to
Federal agencies, such as the U.S. Fish and Wildlife Ser¬
vice, that function under the guidelines of the Interagency
Research Animal Care Committee.
Guidelines for Proper Care and Use of Wiidiife In Field Research 53
Role of Institutional Animal Care and Use
Committees
A major requirement of the Animal Welfare Act and NIH/
NSF guidelines is establishment of institutional facility Ani¬
mal Care and Use Committees (ACUCs). The function of
ACUCs is critical to the conduct of scientific investigations.
Each ACUC must consist of at least three members, one of
whom is the attending veterinarian of the research facility
(or another veterinarian with delegated program responsi¬
bility) and one of whom is not affiliated in any way with the
facility other than as a committee member. The purpose of
the ACUC is to evaluate the care, treatment, housing, and
use of animals and to certify compliance with the Act. This
process involves evaluation of experimental protocols to en¬
sure that animal pain and distress are minimized. ACUC over¬
sight includes laboratory and field studies. Consensus rec¬
ommendations on effective ACUCs for laboratory animals
were provided by Orlans and others (1987). Differences
between laboratory and field studies (Orlans, 1988) do not
negate the need for application of responsible methods for
care and use of animals during field research activities.
ACUCs and field investigators must work together in reach¬
ing agreement on appropriate protocols and methods for spe¬
cific circumstances of the field research to be undertaken.
“Standards for humane treatment of wild vertebrates must
continue to be constantly developed, applied, and re-exam¬
ined. Practices that are acceptable today may well prove un¬
acceptable to tomorrow’s scientific community, and/or to
society in general” (Canadian Council on Animal Care, 1984,
p. 192). Wildlife professionals are strongly encouraged to
serve on ACUCs and contribute their specific knowledge
about the needs of free-living wildlife to help guide Com¬
mittee actions involving protocol reviews for field investiga¬
tions. Wildlife professionals also are encouraged to publish
manuscripts that document the proper care and maintenance
of free-living wildlife species during field investigations.
Development of this information by knowledgeable field bi¬
ologists provides specific species information for guiding
ACUC decisions involving protocol reviews.
I Field research study conditions for wildlife
Irrespective of the species or circumstances involved,
; wildlife professionals should satisfy the following condi-
[ tions for all field research studies. Written assurance that
I these conditions will be met is a prerequisite for project
consideration and funding by many granting agencies.
I- These conditions also are principal points for evaluation
I by the ACUC.
[ 1 . Procedures employed should avoid or minimize dis-
tress to animals consistent with sound research design.
[ 2. Procedures that may cause more than momentary or
J slight distress to animals should be performed with ap¬
propriate sedation, analgesia, or anesthesia, except when
E - justified for scientific reasons in writing by the investiga-
J tor in advance.
S 3. Animals that otherwise would experience severe or
chronic distress that cannot be relieved will be euthanized
I at the end of the procedure or, if appropriate, during the
procedure.
f 4. Methods of euthanasia will be consistent with recom-
i mendations of the American Veterinary Medical Associa-
i tion (AVMA) Panel on Euthanasia (Andrews and others,
i; 1993) unless deviation is justified for scientific reasons
! in writing by the investigator. However, species differ¬
ences must be considered. As noted elsewhere, “The
f AVMA recommendations cannot be taken rigidly for ecto-
1 therms; the methods suggested for endotherms are often
! not applicable to ectotherms with significant anaerobic
J capacities” [American Society of Ichthyologists and Her-
petologists (ASIH), the Herpetologists’ League (HL),
^ and the Society for the Study of Amphibians and Reptiles
r (SSAR), 1987, p. 2].
i 5. Living conditions of animals held in captivity at field
sites should be appropriate for that species and contribute
; to their health and well-being (Fig. 6.1). Specific consid-
; erations include appropriate standards of hygiene, nutri¬
tion, group composition and numbers, provisions for ref¬
uge and seclusion, and protection from weather and other
forms of environmental stress. The housing, feeding, and
r nonmedical care of these animals must be directed by a
l scientist trained and experienced in the proper care, han¬
dling, and use of the species being maintained or studied.
; Some experiments (e.g„ competition studies) will require
: the housing of mixed species, possibly in the same enclo-
i: sure. Mixed housing also is appropriate for holding or
^ displaying certain species.
54 Field Manual of Wildlife Diseases: Birds
Figure 6.1 (A) Temporary “field hospital" for
recovery of waterfowl with avian botulism and
(B) a more permanent structure used for the
same purpose. The permanent structure pro¬
vides shade and has a cement floor for easy
cleaning and disinfection and has a water trough
the birds can swim in. For both situations, peri¬
odic inspection of the pens during each day is
needed for the detection and prompt removal of
dead birds. Prolonged use of the temporary hos¬
pital should be avoided because of fecal con-
I tamination that cannot be readily neutralized. By
I segmenting the temporary facility into separate
I pens, "pasture rotation" followed by treatment of
I vacated areas can help provide reasonably clean
^ holding areas. An alternative would be to con-
f struct pens that can be easily moved. A tarpau-
I lin or other covering placed over the top of the
temporary structure or placement of such struc¬
tures under the shade of trees will enhance bird
survival by minimizing heat stress.
Guidelines for Proper Care and Use of Wildlife in Field Research 55
Wildlife Observations and Collections
General
Before initiating field research, investigators must be fa¬
miliar with the target species and its response to disturbance,
sensitivity to capture and restraint, and, if necessary, require¬
ments for captive maintenance to the extent that these fac¬
tors are known and applicable.
To the extent feasible, animals with dependent young
should not be removed from the wild unless the young also
are collected or removed alive and provided for in a manner
that facilitates their survival beyond the period of dependency.
Whenever possible, voucher specimens of animals, their tis¬
sues, and parasitic and microbial fauna collected during field
investigations should be deposited in catalogued scientific
collections available to others within the scientific commu¬
nity, to provide for maximum use of animals collected.
The number of animals required for investigations depends
on questions being investigated, but provision of adequate
sample size is essential to assure scientific validity of results
and avoid unnecessary repetition of studies. Removal of ani¬
mals from a population (either for translocation or by lethal
means) should be restricted to the fewest animals necessary
to achieve established goals, but should never jeopardize the
population’s well-being.
Investigator Disturbance and Impacts
Potential gains in knowledge from field investigations
must be balanced against the potential adverse consequences
associated with the conduct of the study (Animal Behavior
Society/Animal Society for Animal Behavior, 1986). A high
level of sensitivity to the potential, indirect effects of inves¬
tigator presence and study procedures must be maintained,
and appropriate steps must be taken to minimize these ef¬
fects. Examples of secondary impacts associated with field
investigations may include nest desertion, abandonment of
young, increased vulnerability to predation, traumatic inju¬
ries and mortality resulting from panic escape response,
cessation of breeding activities, increased energy use by dis¬
rupted species, altered feeding behavior, habitat abandon¬
ment, long-term marring of fragile habitats, increased vul¬
nerability to hunting, introduction of disease, and spread of
disease. These effects may impact either research (target) or
other (nontarget) species. Investigators should use available
information on secondary impacts as a basis for taking ap¬
propriate precautions to minimize known potential impacts.
Such factors as frequency and timing of investigator pres¬
ence can influence greatly research effects on target and non¬
target species. When applicable, remote methods of data
collection can be used to minimize disturbance. Also, habi¬
tat conservation should be practiced rigorously during all field
investigations, and every reasonable effort should be made
to leave the study area and access to it as undisturbed as
possible.
Museum Collections and Other Killed Specimens
Collection of animals often is an essential component of
field investigations. These collections may involve system¬
atic zoology, comparative anatomy, disease assessments, food
preference studies, environmental contaminant evaluations,
and numerous other justifiable causes and scientific needs.
Assessment of the need should involve appropriate evalu¬
ations to determine that the proposed collections will pro¬
vide scientific data that are not duplicative of information
already available in the scientific literature (unless confir¬
mation of these data is needed), or that are presently avail¬
able in accessible scientific collections and repositories.
These evaluations also should assess whether suitable infor¬
mation can be obtained from alternative methods that do not
require taking live animals. Methods of collection must be
responsible, minimize the potential for the taking of non¬
target species, and not compromise the purpose of the study.
In some instances it is possible and practical to capture ani¬
mals and then apply approved euthanasia methods (see
Andrews and others, 1993). However, for many field studies
the only practical means of animal collection are those in¬
volving direct killing as the initial step in the collection
process. Under these conditions, methods of vertebrate col¬
lection must be as species or age-class specific as possible.
Methods must not be employed that compromise data evalua¬
tion. Appropriate provisions also must be made for proper col¬
lection and preservation of biological materials associated with
the purpose of the study. Improperly collected or preserved
specimens that fail as useful and valid sources of scientific
information negate the purpose of collecting the animals.
When shooting is the collection method, the firearm and
ammunition should be appropriate for the species and pur¬
pose of the study. The shooter should be sufficiently skilled
to be able to kill the animal cleanly. If an animal is wounded,
immediate attention must be given to appropriate follow-up
actions to kill it quickly. Attention also must be given to the
animal’s location to assure it can be killed cleanly and that it
will be readily accessible for retrieval and data collection.
Kill traps, with attendant baits and attractants, are accept¬
able and effective for animal collection when used in a man¬
ner that minimizes the potential for collecting nontarget spe¬
cies. All traps should be checked regularly, at least daily, to
prevent specimen loss from scavengers and predators and
should be rendered nonfunctional when not in use.
Live traps for nocturnal species should be set before dusk,
checked as soon as possible after dawn, and closed during
the day to prevent capture of nontarget species. Live traps
for diurnal species should be shaded or positioned to avoid
full exposure to the sun. Live traps for nonfossorial mam¬
mals should enclose a volume of space adequate for move¬
ment within the trap; for fossorial mammals, trap diameter
should approximate that of the burrow. The live-trap mecha¬
nism should not cause serious injury to the animal, and trap
56 Field Manual of Wildlife Diseases; Birds
doors should be effective in preventing the captive animal
from becoming stuck or partially held in the door opening
(Ad Hoc Committee on Acceptable Field Methods in Mam¬
malogy, 1987). Pitfalls used as live traps should contain ad¬
equate food to last until the next trap check and should be
covered to keep out rain or punctured to permit drainage.
Blood and Tissue Collections
Only properly trained individuals proficient in the required
techniques should attempt to take tissue samples from live
animals. Collection of tissue samples requires proper ani¬
mal restraint to avoid traumatic injuries to the animal and to
the investigator taking the samples. Use of anesthetics is re¬
quired when the sample procedure will cause more than slight
or momentary pain. The institution/facility ACUC is the
proper source for evaluating collection methods and use of
anesthetics for noninvasive and invasive procedures for tis¬
sue collections from live animals.
Blood is the most common tissue sampled from live ani¬
mals. A conservative rule of thumb is that the amount of blood
drawn at one time from a healthy animal that is to be kept
alive should be no more than 1 percent of its body weight.
However, the amount of blood taken should be limited to
actual needs, rather than the maximum amount that can be
safely taken, to reduce stress from handling. Appropriate
equipment (e.g., needle size) and sample site should be
selected to provide the amount of blood needed for the spe¬
cies involved.
The three most common sites for bleeding birds are the
jugular vein of the neck, medial-metatarsal vein of the leg,
and brachial vein of the wing (Fig. 6,2). The jugular is pre¬
ferred for bleeding most birds because of its accessibility
and size and the relative ease with which large samples can
be taken. The medial-metatarsal vein is not recommended
for use in raptors, nor is the brachial vein in large birds such
as cranes. Feathers should not be plucked to locate these
veins. Birds also can be bled from a variety of other sites
including the heart and occipital venous sinus. However, there
is seldom reason to assume the risk associated with these
sites for nonlethal sampling, even though successful appli¬
cation of these techniques has been demonstrated.
Multiple sites also are available for drawing blood samples
from mammals (Fig. 6.3A). Venipuncture of the cephalic.
Figure 6.2 Blood can be drawn from a variety of sites and
not jeopardize the well-being of birds when properly trained
Investigators utilize appropriate techniques and equipment for
that task. (A) Proper restraint for jugular bleeding of small birds
Is shown and is best accomplished by the person doing the
bleeding. (B) For larger birds such as this blue goose, the
handler supports the body weight and restrains the wings by
cradling the bird against her body while controlling the head
with her other hand. (C) The bleeder normally controls the leg
that blood is being drawn from when the medial-metatarsal
vein Is used. (D) Bleeding from the brachial vein. Care must
be exercised so as not to apply excessive torque to the wing.
Guidelines for Proper Care and Use of Wifdiife in Fieid Research 57
femoral, tarsal, or jugular vein, the orbital sinus, or various
venous plexuses are common procedures. In some instances
cardiac bleeding also is acceptable. Need for anesthesia with
any of these procedures depends upon methods of restraint,
species being bled, physical condition of the animal, and
volume of blood needed. In reptiles, such as turtles, sites for
blood collection are more limited (Fig. 6.3B).
Restraint and Handling
General
Safety of both wild animals and scientists who are study¬
ing them should be the primary consideration when physical
contact between them is judged to be necessary and unavoid¬
able. Nondomesticated animals almost without exception will
try to elude capture, handling, and restraint. The means by
which a particular animal may try to prevent capture will
vary with the species, sex, physiologic condition, and tem-
perment of the individual. In attempts to elude capture, wild
animals are capable of inflicting severe damage to themselves
and their potential captors.
Behavioral characteristics of wild animals often may be
used to assist the potential captor. For instance, animals in a
small pen or cage often voluntarily will enter a smaller con¬
tainer to hide and evade capture. If that container provides
adequate restraint, the potentially dangerous work of secur¬
ing the animal can be accomplished more easily. Every ef¬
fort involving contact between wild animals and humans
should be carefully conceived and skillfully executed. Per¬
sonnel involved must know the habits and behaviors of the
animal to be handled; the plan must have suitable alterna¬
tives; and a genuine regard for the physical, physiological,
and psychological welfare of the animal must be of deep
concern to those actually handling the animals. If the planned
and alternate procedures do not appear to be satisfactory, the
responsible thing to do is cease immediately and return to
the planning stage. Trying to enforce unworkable procedures
in a particular situation is a virtual guarantee of injury to
either the animals or the humans involved.
Physical Restraint
For many situations physical restraint is the most appro¬
priate method of animal handling, because of risks from
chemical immobilization to the animal and humans when
potentially toxic drugs are used. When physical restraint is
selected, an adequate number of sufficiently trained and
equipped personnel must be available to complete the task
safely. Location and type of capture, as well as procedures
to be performed and time required to accomplish them, will
influence the particular type of physical restraint. Gloves,
catch poles, ropes, nets, body bags, holding boxes, corrals,
squeeze chutes, or more sophisticated mechanical holding
devices may be required for specific situations (Fig. 6.4).
For some highly excitable or anatomically fragile species,
prolonged physical restraint without some chemical tran-
quilization may result in self-inflicted trauma, physiological
disturbances, or, occasionally, death. Investigators have an
obligation to make every effort to avoid physical restraint
procedures that result in cardiogenic shock, capture myopa¬
thy, and other stress-induced causes of mortality in their ani¬
mal subjects (Fig. 6.5). Stress-related damage may not be
immediately apparent but may lead to debility or death after
release.
Chemical Restraint
Use of chemicals or drugs to render a wild and poten¬
tially dangerous animal safe to handle has many applications
in wildlife research and management (Pond and O’Gara,
1994). Use of anesthetics, analgesics, and sedatives is man¬
datory for the control of pain and distress before potentially
painful procedures such as surgery are performed on ani¬
mals, Use of drugs and “tranquilizer guns,” however, is not
the panacea to wild-animal restraint. Chemicals used for
tranquilization and immobilization, if not correctly handled
and delivered, may be dangerous to the target animals and
humans (Fig. 6.6). In addition, during the drug induction
phase or during recovery, an unrestrained animal may be
subject to increased potential for accidental injury or death
including predation. While under the effects of the drug the
animal may become hyper- or hypothermic, depending on
chemicals used and ambient temperature, it may vomit and
aspirate the vomitus, or pregnant females may abort. A darted
animal may be able to elude its captors and hide before
being completely anesthetized, a particularly acute hazard
when chemicals are employed that require administration of
an antidote. All of these circumstances and possibilities must
be understood and evaluated by the researcher before a chemi¬
cal is selected as the best method of restraint in a given in¬
stance.
If chemical restraint is selected, it is imperative for all
members of the capture team to have a working knowledge
of the chemical or drugs being used, even if they are to be
handled and delivered by a veterinarian. It also is the re¬
sponsibility of researchers to know the effects, side effects,
advantages, and disadvantages of the drugs being used, and
to have knowledge of such factors as the minimum and maxi¬
mum induction times and potential for adverse drug reac¬
tions. This type of information is necessary to evaluate the
danger to target animals, and to humans that might be ex¬
posed to the drugs. Searchers should be capable of monitor¬
ing the condition of anesthetized animals and be able to ap¬
ply resuscitative routines in a life-threatening emergency.
Specific recommendations for drug use and their dosage, drug
delivery systems, and physical restraint techniques applicable
to the specific species are available in the published litera¬
ture (Pond and O’Gara, 1994). Information on use of these
methods exists in guidelines on acceptable field techniques
by various professional societies (See “Professional society
guidelines” at the end of this chapter).
58 Field Manual of Wildlife Diseases: Birds
Figure 6,4 (A) Squeeze chutes and head restraints can
allow a blood sample to be safely taken from the jugular of
large ungulates. (B) Poisonous animals such as this rattle¬
snake should only be handled by well-trained personnel that
have experience with these types of species.
Guidelines for Proper Care and Use of Wildlife in Field Research 59
Figure 6.5 (A) The pale coloration of the muscle tissue of the right leg and discolored areas of muscle
tissue in the ieft leg of this whooping crane are iesions of capture myopathy due to stress associated with
improper/extended restraint. (B) The iight area in this piece of ieg muscie from an antelope Is also due to
capture myopathy.
60 Field Manual of Wildlife Diseases: Birds
Photos by Julie Langenberg, International Crane Foundation
Figure 6.6 Extensive tissue damage and
hemorrhage, such as seen in the tissues of
this black bear, can occur from immobilization
with a CO^ projected dart.
Animal Marking
Developing means of reliably identifying individual ani¬
mals to achieve field research objectives often is necessary.
In addition to requiring individual identification, research¬
ers may need information on nonconspicuous aspects of
physiology or movements, or other aspects of animal ecol¬
ogy that can be determined directly or indirectly through
specially designed markers.
Consideration for animal marking
Before initiating any marking procedure for wild ani¬
mals, researchers must resolve the following questions
to determine whether marking is required and appro¬
priate for the particular situation.
1 . Do naturally occurring differences in the morphol¬
ogy of the animals under consideration provide suffi¬
cient identification to achieve research objectives?
2. How may animals must be individually identifiable?
3. If animals must be physically marked, can a suffi¬
cient number of animals be marked in the time avail¬
able?
4. Are the risks (to both the animal and researcher)
associated with capture, handling, and marking, and
subsequent well-being, minimal and acceptable in both
responsible and scientific contexts?
If the marking process causes pain or distress, as defined
by the Animal Welfare Act, appropriate analgesics or anes¬
thetics should be used.
Criteria for Marking
When answers to the four initial questions lead to a deci¬
sion to initiate an animal-marking program, researchers must
search among a wide array of potential techniques with vary¬
ing strengths and weaknesses to select the method(s) most
suited to their particular project (Nietfeld and others, 1994).
Technological and methodological constraints and available
resources can vary widely from project to project and will
require each researcher to examine each potential marking
technique in terms of a standard set of criteria. Specific cri¬
teria relate to impacts of marking on the organism, validity
of the study, and other constraints such as legal requirements.
Evaluation criteria for marking techniques
The following are essential criteria for evaluation of
marking techniques:
1. Marks should have minimal effect on the anatomy
and physiology of the organism, i.e., no immediate or
long-term physical hindrance.
2. Marks should not influence the organism’s behav¬
ior, i.e., they should not reduce an organism’s ability
to secure food or inhibit breeding activity (unless the
marks are intended as a reproductive inhibitor).
3. Marks that make an organism more conspicuous
must be evaluated carefully to ensure that they neither
cause others of the same species to react differently to
it than to other conspecifics nor subject it to increased
selection by potential predators (unless this is a pur¬
pose of the study) (Fig. 6.7).
4. Marks should be retained for the minimal period
required to achieve project goals.
5. Unambiguous marks that are quick and easy to ap¬
ply should be selected to avoid extensive handling or
error potential.
6. Marks must comply with Federal, State, and other
agency rules and regulations.
The first three criteria focus on the well-being of the or¬
ganism being studied and the potential for marks to influ¬
ence research results by affecting the fitness or behavior of
the organisms. Criteria 4 and 5 may affect the validity of the
research design, and criterion 6 reflects other constraints
placed upon the researcher. Violation of any of the first five
criteria may result in biased research results, so researchers
should specifically address these criteria in any evaluation
of research resulting from a sample of marked organisms.
Although marks that may be applied to organisms are
commonly perceived as passive and visual, markers also
Guidelines for Proper Care and Use of Wiidiife in Fieid Research 61
Figure 6.7 (A) Color marking waterfowl should be done with rapidly drying paints and (B and C)
the painted feathers heid separated until the paint dries to prevent the feathers from sticking to one
another and hindering normal flight
exist that are active and visual (lights), that are auditory, that
feature radiotelemetry, or that rely on chemical detection.
A vast literature exists of techniques and potential concerns
regarding the marking of organisms from insects to whales,
and it has been summarized in detail elsewhere (see “Profes¬
sional society guidelines”; Day and others, 1980; Orlans,
1988).
Other Professional and Ethical Considerations
Many organisms of interest to wildlife professionals are
free-ranging and may be enjoyed by other segments of soci¬
ety in many ways, from observation or photography to har¬
vest as meat or trophies. Professional ethics dictate that those
other potential uses of organisms be considered and accom¬
modated insofar as possible. Wild animals and birds are val¬
ued in part because they are wild, and the presence of human-
caused marks may detract from that value. Accordingly, short¬
lived and inconspicuous marks should be selected whenever
they can meet the objectives of proposed research. Scientists
have an ethical responsibility to attempt to remove collars or
other external markers at the conclusion of their research if
possible and feasible. Furthermore, professional and ethical
considerations dictate that permanent markers that injure or
change the appearance of an animal (e.g., toe-clipping, brand-
62 Field Manual of Wildlife Diseases: Birds
ing, and tattooing) be employed only under the most humane
conditions and when alternate methods are not available to
achieve desired research objectives.
Housing and Maintenance of Field Sites
General
Proper care and responsible treatment of incarcerated ani¬
mals must depend on scientific and professional judgement,
on concern for the animal, on knowledge of animal behavior
and animal husbandry, and on familiarity with the species.
Investigators working with species unfamiliar to them should
obtain all pertinent information before confining those ani¬
mals. It also may be necessary to test and compare several
methods of housing to determine the most appropriate one
for the well-being of the animal and the purpose of the study.
Findings should be part of a permanent record system and
animal logbook associated with the study and the mainte¬
nance facility.
Housing
Housing for wild vertebrates should approximate natural
conditions as closely as possible. Housing should provide
safety and comfort for the animal as well as meet the study
objectives. Methods of housing should provide for behav¬
ioral needs, safety, adequate exercise and rest, and condi¬
tions for the general well-being of the animal. Considerations
depend on the animal involved and include isolation or ref¬
uge areas, natural materials, dust and water baths, natural
foods, sunlight, and fresh air. Housing should incorporate as
many aspects of natural living as possible, such as brushy
areas for escape, resting cover, shade and protection from
environmental elements, a natural stream traversing the pen,
rocky areas for hoofed animals that need to wear down their
hooves, and social groups of animals kept together. Housing
of compatible species in a common pen also will provide for
social interaction. Frequency of cleaning should be a com¬
promise between level of cleanliness necessary to prevent
disease and amount of stress imposed by cleaning (Fig. 6.8).
In general, housing must be of adequate size to allow for
the physical and behavioral needs of the animals, while
allowing scientists to collect appropriate data. For many hous¬
ing situations, the pen can be large and natural, with a smaller
internal or attached catch pen to restrain animals for experi¬
mental techniques. Pen construction materials must provide
for the safety of the animals, as well as prevent the animals
from escaping. Materials should be of sufficient durability
to last for the intended period of confinement. When long¬
term confinement (weeks or longer) is necessary, or pens are
to be reused, materials with impervious surfaces should be
used to facilitate sanitation and minimize the potential for
survival of animal pathogens. All animals that are inherently
dangerous, are environmentally injurious, or have a propen¬
sity for escape require special attention. Double walls or
Figure 6.6 A high quality enclosure for New Zealand black
stilt that approximates several aspects of the natural habitat
and provides safety and comfort for the birds.
double enclosures, covered tops of enclosures, and construc¬
tion with metal bars or chain link may be required, depend¬
ing on the species. Mesh size and spacing between fencing
materials must be small enough to prevent the head of an
animal from extending through the fence. Smaller fencing
mesh also is more visible to animals. Colored flagging ma¬
terial may be necessary for animals to visualize fencing un¬
til they become accustomed to it. Animals should be released
into the housing in a calm and unstressed manner so that
initial mortality and morbidity from fence encounters are
minimal. A small dose of tranquilizer often will reduce the
immediate flight response when an animal is released into
the housing and may help prevent initial injuries. Once ani¬
mals have investigated the limits of the housing, injury oc¬
currence is minimized if investigators do not cause undo flight
reactions.
Adequacy of housing often can be judged on normal be¬
havior patterns, weight gains and growth, survival rates, re¬
productive success, and physical appearance of the animals
involved in the research project. Established guidelines for
housing laboratory and farm animals were provided by the
Canadian Council on Animal Care (1980, 1984). Additional
guidelines for housing requirements of fish, amphibians rep¬
tiles, wild birds, and small mammals were reported by the
appropriate professional societies and appear in the Animal
Welfare Act (see also “Professional society guidelines” at
the end of this chapter).
Nutrition
Nutrition must meet the needs of the animal unless devia¬
tions are an approved purpose of the investigation. Research¬
ers are responsible for determining the appropriate nutritional
needs of study animals prior to placing them in confinement
and for obtaining adequate food supplies to sustain the ani¬
mals during the period of confinement. Feeding and water¬
ing should be under the direct supervision of an individual
Guidelines for Proper Care and Use of Wildlife in Field Research 63
Photo by Milton Friend
trained and experienced in animal care for the species being
maintained. Animal care personnel must be familiar with the
animals being Studied so abnormalities in appearance and
behavior that may be indicative of nutritional deficiencies
can be recognized quickly.
Transportation
General Considerations
A variety of vehicles such as conventional motor vehicles,
all-terrain vehicles, snow machines, rotary and fixed-wing
aircraft, and boats are used to transport wild animals. The
species involved, method of transportation selected, and
length of time an animal is to be transported are important
factors regarding the type of care and conditions of contain¬
ment required to maintain the animal in a state of well¬
being (Fig. 6.9). To the extent possible, selection of trans¬
portation vehicles should take into account maintenance of
the animal in a comfortable environment. Veterinary assis¬
tance may be required to prescribe and administer appropriate
tranquilizers or other drugs when conditions of transporta¬
tion are likely to result in a high level of stress to the animal
due to its behavioral and physiological characteristics, re¬
strictions of confinement, engine noise, and rigors of the trip.
The transportation process should be as brief as possible.
This can be expedited by proper and adequate planning to
assure that transportation vehicles and housing units in ap¬
propriate numbers and size are available and ready for use
as needed; that food, water, bedding, and other needs to pro¬
vide for the animals also are available; that individuals in¬
volved in the transportation process are trained in the proce¬
dures to be used in containment and transportation of the
Figure 6.9 (A) Restraint of big¬
horn sheep being translocated
via helicopter. The legs have
been immobilized to prevent in¬
jury to the animal and holders.
(B) Blinders on this caribou re¬
duces stress from the presence
of humans. Legs are restrained
similar to the procedure shown
for the bighorn sheep.
64 Field Manual of Wildlife Diseases; Birds
Photos by Julie Langenberg, International Crane Foundation
animals; and that all permits, health certificates, and other
paperwork have been completed to the extent possible.
When interstate movement of animals or shipment by
commercial carriers is involved, scheduling of transporta¬
tion segments to minimize the number of transfers and de¬
lays between transfers, having someone involved with the
project meet the shipment at each transfer point, and, when
appropriate, arranging for prompt clearance of animals by
veterinary and customs inspectors can result in major reduc¬
tions in transit time. The receiving party should be on-site
when the animals reach their destination.
For some species, periodic rest periods are required to
allow the animals to feed undisturbed. Other species are best
transported when they are normally inactive and do not feed.
Ventilation within the housing unit and transportation ve¬
hicle should provide for adequate air movement to keep ani¬
mals comfortable and avoid buildup of exhaust gases. Sub¬
dued lighting and visual barriers between animals and hu¬
mans and between animals and their transportation environ¬
ment should be provided to help keep the animals calm. The
U.S. Fish and Wildlife Service has published rules for the
Humane and Healthful Transport of Wild Animals and Birds
to the United States (see Fed Reg. 50 CFR Part 14).
Confinement During Shipping
Animal containers should be inspected to assure they have
no sharp edges, protrusions, or rough surfaces that could
cause injury during transport. When appropriate, containers
also should be padded to help prevent injury. The floor of
shipping containers should allow reasonable footing to pre¬
vent falling due to a slippery surface. Also, containers should
not have coatings or be constructed of materials that are toxic
and could be consumed by the animal through licking or
chewing during transportation. In general, housing units of
porous materials, such as cardboard boxes, should not be
reused; all other containers used to house animals should be
suitably disinfected between uses (Fig. 6.10). That portion
of the transportation vehicle used to contain the housing units
also should be disinfected.
Grouping or separation of animals being transported at
the same time should take into consideration the species, age,
and other appropriate factors. Direct contact generally should
be maintained between females and their dependent young,
particularly if abandonment may result (unless the young
are to be maintained by some other means). Birds should be
isolated in separate cells within the shipping container; if
this cannot be done, each individual should have sufficient
space to assume normal postures and engage in comfort and
maintenance activities unimpeded by other birds (Ad Hoc
Committee on the Use of Wild Birds in Research, 1988).
Health Aspects
For short-term transportation (less than 30 min), basic con¬
siderations are to prevent pain, injury, and undue stress. Ther¬
moregulation capabilities of the species must be considered
when an animal is removed from its existing environment
and placed in the transportation environment. Transported
animals should be protected from exposure to inclement
weather, harsh environmental conditions, and major tempera¬
ture fluctuations and extremes.
Bedding, feed, and water should be provided, as appro¬
priate, and the animals should be observed periodically to
determine their state of well-being during transportation. On¬
site veterinary assistance may be warranted to monitor ani¬
mals and to provide life-support assistance should a medical
emergency occur during transportation or at the release or
field study site. Selection of veterinary assistance should
focus on the individual’s knowledge and experience with the
wildlife species involved. Any animals that die during tran¬
sit should be removed as soon as practical from the sight and
olfactory detection of other animals being transported. These
carcasses should be retained for pathological examinations
regarding cause of death. Similarly, animals that become
severely injured or clinically ill should be removed and re¬
sponsibly euthanized. Euthanasia should not take place in
the presence of other live animals. Sick animals disposed of
in this manner also should be retained for pathological as¬
sessments. Determinations of cause of death are needed to
assess whether the remaining animals are at risk from patho¬
gens associated with the dead animals.
Surgical and Medical Procedures
Guidelines for wildlife medical procedures
; Wildlife field research can involve surgical and medi¬
cal procedures such as implanting radio transmitters
and surgical sex determination in birds. Incorporation
j of such techniques into a research protocol should fol-
; low these guidelines:
1. Surgical and medical techniques used should be
S based on accepted protocols for the studied species or
for the most closely related domesticated species. The
Canadian Council on Animal Care’s (1984) Guide to
the Care and Use of Experimental Animals, Volume 2,
is a good source of such information.
2. Protocols should be developed and, if possible,
implemented in collaboration with a qualified veteri¬
narian. Only properly trained personnel, conversant in
! all techniques necessary, should conduct the proce-
j dures.
3. Protocols must be reviewed carefully by the ACUC
with special attention paid to limiting pain during the
actual procedure and post-procedure period.
4. Adequate anesthesia and/or analgesia must be pro¬
vided.
Guidelines for Proper Care and Use of Wildlife in Field Research 65
Figure 6.10 (A) Canada geese restrained
within burlap bags with openings for the head
and neck for short-distance transportation by
vehicle. (B) Porous materials such as these bags
and the cardboard boxes these Hungarian par¬
tridge are being released from should not be
reused for animal transport More permanent
holding containers such as (C) plastic poultry
crates and (D) large animal crates should be thor¬
oughly washed and disinfected between uses.
66 Field Manual of Wildlife Diseases: Birds
Minor Procedures
Minor medical procedures such as collection of blood,
administration of drugs intravenously or intramuscularly,
biopsies of superficial structures such as skin, and sutured
attachment of radio transmitters usually can be performed
safely and responsibly in the field without complicated equip¬
ment. However, it is the researcher’s responsibility to choose
the least invasive and least painful technique, minimize the
duration of the procedure, use the most appropriate equip¬
ment and aseptic technique, and provide analgesia or seda¬
tion when indicated.
Major Procedures
As defined by the Animal Welfare Act, major operative
procedures are (p. 36,121) “any surgical intervention that
penetrates and exposes a body cavity or any procedure which
produces permanent impairment of physical or physiologi¬
cal functions.” Major surgical procedures, when survival of
the animal is intended, should be performed only under proper
anesthesia and with sterile technique. Examples of major
procedures used in wildlife research include laparotomy,
surgical flight restraint, and sterilization. These procedures
should be performed only in a clean space set aside for ster¬
ile surgery, with surgical instruments and drapes of the proper
type, and with anesthesia protocols judged to be safe and
responsible for the species involved. Necessary equipment
and trained personnel to deal with surgery or anesthesia-
related emergencies (i.e., severe blood loss, cessation of
breathing or cardiac function, severe hypo- or hyperthermia,
acid-base imbalances) should be available at all times. This
will maximize the success and subsequent scientific return
from those often costly procedures and, therefore, minimize
the number of animals needed and amount of animal dis¬
tress (Fig. 6.11).
Figure 6.11 Invasive surgical procedures should be done
only by properly trained personnel knowledgeable of tech¬
niques necessary to successfully carry out the procedure and
appropriately respond to medical emergencies that might
arise.
Medical Considerations
Wildlife field researchers should have access to veteri¬
nary consultation and take responsibility to prepare them¬
selves to deal with any health problems that might arise in
their study population. Sometimes intervention and control
of a natural disease process may not be advisable and may
interfere with the study’s goals. However, if the health prob¬
lem arises due to the researcher’s work, or if it will interfere
with the study, the researcher must be ready to respond. Prepa¬
rations should include gaining familiarity with the common
diseases and health problems of the species under study, es¬
tablishing a contact with a veterinary consultant, and having
appropriate treatment or control equipment and drugs on hand
or easily accessible. The researcher also is responsible for
evaluating the possible impact of disease in the study ani¬
mals on the larger population or ecosystem as a whole, and
for making the maintenance of their welfare a priority as
decisions are made. This is especially true when release or
translocation of animals is part of a study; disease must be
considered in evaluating the advisability of the program.
Euthanasia
Euthanasia is defined under the Animal Welfare Act as
(p. 36,121) “the humane destruction of an animal accom¬
plished by a method that produces rapid unconsciousness
and subsequent death without evidence of pain or distress,
or a method that utilizes anesthesia produced by an agent
that causes painless loss of consciousness and subsequent
death.” Euthanasia may not be an approved component of a
field study, but it may become a necessary health care option
in a study involving capture, restraint, or surgical procedures.
Therefore, all wildlife researchers involved in invasive stud¬
ies must be familiar with the approved euthanasia methods
for their study species (Andrews and others, 1993) and have
the appropriate equipment/drugs on hand so euthanasia can
be performed quickly.
Disease Considerations
Field investigators need to be fully aware of disease con¬
cepts so they may avoid introduction of new disease prob¬
lems into animal populations or the spread of disease to other
populations and locations as a result of their studies. Dis¬
ease introductions and spread occur as a result of animals
brought to the field research site to serve as biological senti¬
nels, as decoys to lure and capture other animals, for species
introductions or releases to supplement existing populations,
for behavioral studies, for assistance in tracking or retriev¬
ing animals, and for other purposes. All of these uses of ani¬
mals involve acceptable methods for scientific research and
wildlife management. However, under no circumstances
should the well-being of free-ranging wildlife populations
be unduly jeopardized by disease risks associated with ani¬
mal use in field research. Field investigators have ethical and
Guidelines for Proper Care and Use of Wildlife
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