Human-Animal Medicine. Clinical Approaches to Zoonoses, Toxicants, and Other Shared Health Risks

460 Pages·2010·102.427 MB·English

by  Peter M. Rabinowitz, MD, MPH, and Lisa A. Conti, DVM, MPH, DACVPM, CEHP (Eds.)

1
The Convergence of
Human and Animal
Medicine
Laura H. Kahn, Bruce Kaplan, and Thomas P. Monath
How Human and animal HealtH Food animals
converge
On a global scale, the growing human population has
led to a rapid and unprecedented increase in the num-
The relationship between human and animal health is becom-
bers and density of animals raised for food production in
ing increasingly complex and includes biological, chemical,
many parts of the world and the United States (see Chapter
physical, and social factors (Figure 1-1). Both endemic and
11). The rearing, transportation, marketing, and process-
newly emerging infectious diseases have grabbed headlines
ing of these animals have significant implications for the
and heightened awareness of the role of wild and domes-
occupational health of the human beings working with
tic animal populations in transmitting diseases to human
the animals (Figure 1-3); wildlife that may have contact
beings. Although the importance of zoonotic disease is not
with such animals; as well as the air, soil, and water qual-
new—approximately 60% of all infectious pathogens of
ity of agricultural areas (see Chapter 12). The widespread
human beings are zoonotic in origin—an even higher per-
outbreaks of avian influenza among domestic poultry and
centage of newly emerging diseases over the past 2 decades
the threat of the emergence of new strains with pandemic
are zoonoses, many originating from wildlife (Figure 1-2).1
potential are a reminder of these connections. In addi-
All but one of the bioterrorism agents considered to have the
tion, the increasing reliance on bush meat consumption
highest potential for use as a weapon of biological warfare
in many developing countries affects wildlife populations
are zoonotic pathogens.
and species diversity and exposes human beings to zoonotic
disease threats.3
Pets and wildlife
More than half of households in the United States own
a dog, cat, or both. In addition, millions of exotic wild tHe imPortance oF environmental
animals, birds, and reptiles are kept in U.S. households as HealtH to Human beings and otHer
pets, and the worldwide trade in such animals is accelerat- animals
ing (see Chapter 10).2 Therefore the average patient visiting
his or her health care provider is likely to share his or her Zoonotic disease represents just one of the ways that the
living space with a pet, and the health of the pet (which health of companion animals, livestock, and wildlife is inex-
may have originated in a wildlife population across the tricably linked with human health. The global environment
globe) may hold clues to health or disease issues that the is rapidly changing, and animals and human beings are
patient is experiencing. Furthermore, as suburban develop- exposed to shared environmental health risks. Environmental
ments encroach on wildlife habitat (see Chapter 6), con- disasters such as Hurricane Katrina wreak havoc on both
tact with domestic animals, wildlife, and insect vectors may human and animal populations. Many zoonotic diseases
be frequent, allowing pathogens to pass in both directions are emerging as a result of environmental factors, including
and bringing human beings into the mix. At the same time, climate change, deforestation, alterations of wildlife habi-
veterinarians in small animal practice have understood tat, and other land use change4; human population growth;
for years that pets contribute to improved human mental movement of human beings and animals across borders;
health and well-being and that the benefits of compan- and increased production of food animals. The built envi-
ion animals usually far exceed the risks of zoonotic dis- ronment may contribute to a sedentary lifestyle and mani-
ease. A growing body of research now supports the concept fest as an obesity epidemic in both human beings5 and their
of this “human-animal bond phenomenon”; avenues for pets (Figure 1-4). Animals and human beings often share
physician- veterinarian cooperation to maximize these exposure risks from noninfectious disease threats, such as
benefits are detailed in Chapter 5. air and water quality problems, pesticides, lead, and carbon
1
2 Human-animal medicine
Environmental health (biologic,
chemical, physical, and social factors)
“Shared risk” and
sentinel health events
Animal health
Human health
Figure 1-3 n Removing the breast and leg meat from a bird without
using gloves. (Courtesy Melissa Anderson. From Auerbach PS: Wilderness
medicine, ed 5, Philadelphia, 2007, Mosby Elsevier.)
Figure 1-1 n Relationships among environmental, human, and animal
health.
EXAMPLES OF ROUTES BY WHICH ZOONOSES ARE ACQUIRED
Direct Contact with Contact Fecal–oral Bites and Via Eating Ingestion Respiratory
contact animal with urine route scratchesectoparasites under- of milk route
products carrying cooked
pathogens meat, fish
Dermatophytes Anthrax Leptospirosis Salmonellosis Rabies Ticks: Rocky Trichinellosis Mycobacterium Histoplasmosis
Mountain bovis
Tularemia Toxoplasmosis
spotted fever,
Streptococcus
tularemia, Taenia solium
zooepidemicus
Lyme disease,
babesiosis
Fleas: Plague
Figure 1-2 n Examples of routes by which zoonoses are acquired by human beings. (From Cohen J, Powderly
WG: Infectious diseases, ed 2, London, 2003, Mosby Elsevier.)
monoxide. Just as canaries once warned coal miners of the a diagnosed disease that provides information about an
presence of deadly gases and dead songbirds sent a mes- environmental risk to animals living nearby. Chapter 4 in
sage to human beings about the risks of pesticides in Rachel this book, as well as the disease-specific chapters, provide
Carson’s Silent Spring, a disease occurrence in an animal can many examples of sentinel events and how clinicians and
be a “sentinel event” warning human beings of an environ- public health professionals can detect them and act on such
mental threat.6 Alternatively, at times a human being has information to prevent further cases.
Chapter 1 n the convergence of Human and animal medicine 3
in important ways. Table 1-1 outlines some of the key points
differentiating the groups.
Despite many curricular similarities between human
medical and veterinary medical schools, veterinarians
receive more training in zoonotic diseases, whereas medical
students learn virtually nothing about animal health issues.
Both groups receive only limited training in public health
theory and practice.
After completing their training, physicians in practice
rarely make home or worksite visits to directly see the
environments where their patients live and work, whereas
large animal veterinarians frequently visit farms. Public
health professionals may be more likely to visit locations
where environmental health threats have been identified.
The rate at which veterinarians perform necropsies on
animals that have died may be higher than the rate at which
Figure 1-4 n Obese Savannah monitor (Varanus exanthematicus). physicians perform autopsies. As a result of these training
(Courtesy S.J. Hernandez Divers. From Mader DR: Reptile medicine and sur- and practice differences, the approaches to detecting and
gery, ed 2, St Louis, 2005, Saunders Elsevier.) preventing problems related to interactions among human
beings, animals, and the environment may differ greatly
similarities and diFFerences among among these groups.
tHe training and Practice oF Human
HealtH, animal HealtH, and Public
role of veterinarians in Human Health
HealtH ProFessionals
Many physicians may not be aware of the routine contri-
The training and practice patterns of human health care pro- butions made by practicing veterinarians to human health.
viders, veterinarians, and public health professionals differ Veterinarians regularly educate pet owners and farmers
Table 1-1 n Training and Practice Statistics: Veterinary Medicine, Human Medicine, and Public Health
Veterinary Medicine Human Health
Category (DVM/VMD)7 (MD, DO)7 Public Health (MPH, DrPH)
minimum years of 4 4 2-4
professional school approximately 2 years basic approximately 2 years basic studies include epidemiology,
sciences + 2 years clinical studies sciences + 2 years clinical studies biostatistics, and public health
curricula comparable to medical curricula comparable to administration
schools veterinary medical schools
amount of training in moderate minimal varies
zoonotic diseases
amount of training in animal High8 none varies (e.g., there are combined
health issues dvm/mPH programs)
curriculum hours in public minimal minimal High
health
number of practitioners in the approximately 69,170 (active)8* 633,000 †
united states
specialties 70% of private practice Primary care professions includes environmental health,
veterinarians focus on small specialists occupational health, maternal
animal medicine/surgery and child health, infectious
(dogs, cats, etc.) diseases, biostatistics
board certifications in various
specialties
Practice organization Prevailing model solo or increasing role of health Public health agency
small group practices with some maintenance organizations
evolving large group practices
House calls/site visits large animal dvms/vmds visit mds rarely make house calls some public health
farms; rare for small animal Home health care nurses professionals perform site
practitioners (via mobile provide many services in visits
veterinary clinics) homes
licensing agency in states departments of consumer affairs, professional regulation, or departments of public health (usually the
same department in state)
*As of October 31, 2007.
†Data not available.
4 Human-animal medicine
about the risks of acquiring zoonotic diseases. They reduce health issues. They often interact with their federal colleagues
transmission risks to human beings by vaccinating large at the CDC and other professionals in state and federal
numbers of pets and livestock against zoonotic diseases. departments of agriculture on issues related to food safety,
Many are involved in caring for wildlife and exotic animals. importation of animal diseases, bioterrorism preparedness,
The expanding role of veterinarians at the U.S. Centers for pandemic preparedness, environmental health, and many
Disease Control and Prevention (CDC, http://www.cdc.gov) areas of shared concern (see Chapter 13).
reflects a growing trend to create joint teams of veterinarians
and human health professionals to deal with human-animal
other Professionals critically involved with
health issues. The team approach has proved synergistic; more
Human-animal medicine issues
rapid and precise evaluations enhance more efficacious con-
trol. At the time of this writing, approximately 90 veterinarians In addition to physicians, veterinarians, and public health
work at the CDC.9 The CDC’s National Center for Zoonotic, professionals, many other professionals play key roles in
Vector-Borne, and Enteric Diseases (NCZVED) provides lead- human and animal health and should be considered in any
ership, expertise, and service in laboratory and epidemiological discussion of how these fields converge. A significant percent-
science, bioterrorism preparedness, applied research, disease age of health care services in the United States is provided by
surveillance, and outbreak response for infectious diseases. Its advanced practice registered nurses (APRNs) or physician
ecological framework includes human beings, animals, and assistants (PAs), and hospital-based and home health nurses
plants interacting in the complex, changing natural environ- perform frequent health assessments and contribute to the
ment. Until September 1, 2009, NCZVED was directed and development of care plans. On the veterinary side, veterinary
administered by a veterinarian with previous experience as technicians and other veterinary staff provide many animal
administrator of the U.S. Department of Agriculture’s (USDA) health care services, as do wildlife rehabilitators. Public
Animal and Plant Health Inspection Service (APHIS). health efforts to manage zoonotic disease risk and other
From 1953 through 2008, more than 228 veterinarians environmental health issues require the expertise of vector
have completed the Epidemic Intelligence Service (EIS) ecologists, wildlife biologists, disease ecologists, environ-
training at the CDC (Figure 1-5). The EIS represents the mental health professionals, industrial hygienists, toxicolo-
U.S’s critical unit for investigating the causes of major epi- gists, anthropologists, farmers, and agricultural extension
demics. Over the past 50 years, EIS officers have played cru- officers, among others. Although human health and animal
cial roles in combating the root causes of epidemics of major health clinicians may detect sentinel cases of disease related
consequence. The EIS has served as a model for similar ser- to environmental factors, the actual intervention to improve
vices in about 25 other countries worldwide. such environments requires a team approach of diverse pro-
The Special Pathogens Unit at the CDC concerns itself fessionals, as is described in other sections of this book.
with the investigation of the highly pathogenic, zoonotic viral
hemorrhagic fevers, such as Ebola virus, Marburg hemor-
rhagic fever, and Lassa fever. The unit is currently directed by eFForts to bridge tHe gaPs between
a veterinarian and includes a number of physicians who col- Human and animal HealtH
laborate on laboratory and field research aimed at elucidating
the reservoirs of infection in nature, transmission of viruses
communication between Human and animal
to human beings, the control of outbreaks, and ground-
Health care Providers
breaking research on diagnostic methods and vaccines.
Outside the CDC, state public health veterinarians (http:// The convergence of these health issues involving human
www.nasphv.org) are involved in a wide range of public beings and other animals would seem to demand ongoing
Figure 1-5 n A CDC investigator examines a calf as part of an outbreak investigation. (Courtesy Centers for
Disease Control and Prevention, Atlanta, Ga.)
Chapter 1 n the convergence of Human and animal medicine 5
and substantive interactions between human health care as conservation medicine,13 Ecohealth,14 and “One World,
providers and veterinarians, as well as a shared body of One Health.”15 The common theme of these diverse efforts
knowledge regarding health links between human beings is that the health of human beings, wildlife, domestic ani-
and animals. Yet professional interaction of this type is often mals, and the environment is vitally interconnected and
limited. Research indicates that many physicians and other future efforts to improve global health must take these
health care providers may be uncomfortable discussing ani- interrelationships into account.
mal health issues with their patients.10 Veterinary medi- Recently the American Medical Association (AMA)
cal health care providers may be cautious about discussing and American Veterinary Medical Association (AVMA)
human health issues with their clients, in some circumstances began collaborative efforts on a One Health Initiative (also
because of caution to not overstep professional boundaries referred to as One Medicine, One Medicine-One Health, and
and possibly because of concerns about malpractice liability One World One Medicine One Health). The One Health
or privacy issues (see Chapter 2). Both human health and Initiative promotes the model of physicians, veterinarians,
veterinary clinicians may be unfamiliar with public health and allied medical and environmental scientists in clini-
and environmental health concepts and their relevance to cal, public health, and biomedical research settings working
their practices. more closely together than in the past to better understand,
Some of the key differences among the professions, as well manage, and prevent health risks involving animals, human
as the One Health Initiative aimed at overcoming professional beings, and their environments (Figure 1-6).11,16
barriers to communication and collaboration, are described A joint One Health Task Force created by the AMA and
below. AVMA was formed to study ways to facilitate collabora-
tion and cooperation among human health and animal
health professions, educational institutions, and agencies
collaborations between animal and Human
to improve assessment, treatment, and prevention of cross-
Health care Providers
species disease transmission and mutually prevalent nonin-
Historical precedents do exist for productive collabora- fectious human and animal diseases and medical conditions.
tion between animal and human health care providers. The recommendations of the One Health Task Force were
The nineteenth-century physician pathologist Dr. Rudolf published in 2008 (available online at http://www.avma.
Virchow (who coined the term zoonosis) emphasized the org/onehealth).17 Key recommendations of the task force
need for medical scientists to learn from comparative medi- included a call for a national research agenda for One Health
cine approaches to research. Sir William Osler (called the and outreach efforts to involve medical, veterinary medical,
“Father of Modern Medicine”), a physician who studied with and public health students and their respective organizations
Virchow, helped establish the first departments of veteri- in One Health concepts.
nary pathology in North America in the late nineteenth cen- Similarly, a consultation document, “Contributing to
tury. Drs. Theobald Smith, a physician, and F. L. Kilborne, a One World, One Health: Strategic Framework for Reducing
veterinarian, discovered that Babesia bigemina, the cause of Risks of Infectious Diseases at the Animal-Human-
cattle fever, was transmitted by ticks. Their work set the stage Ecosystems Interface,” was produced by the Food and
for Walter Reed’s discovery of yellow fever transmission via Agriculture Organizations of the United Nations (FAO),
mosquitoes.11 More recently, Rolf Zinkernagel, a physician, World Organization for Animal Health (OIE), World
and Peter C. Doherty, a veterinarian, shared the 1996 Nobel Health Organization (WHO), United Nations System Influ-
Prize for their discoveries of how the body’s immune system enza Coordination, United Nations Children’s Emergency
distinguishes normal cells from virus-infected cells. Funds (UNICEF), and the World Bank (see http://www.
oie.int/downld/AVIAN%20INFLUENZA/OWOH/
OWOH_14Oct08.pdf).
one Health initiative The six specific objectives suggested for prioritization by
national authorities are as follows:
In the 1960s, veterinarian Dr. Calvin W. Schwabe, a para-
sitologist and veterinary epidemiologist, coined the term 1. Develop international, regional, and national capacity in
One Medicine in his textbook, Veterinary Medicine and surveillance, making use of international standards, tools,
Human Health.12 Schwabe proposed a collaborative effort and monitoring processes
between veterinary and human health professionals to 2. Ensure adequate international, regional, and national
combat zoonotic diseases. In recent years, a number of capacity in public and animal health—including com-
organizations and collaborations have sought to build on munication strategies—to prevent, detect, and respond to
and further expand this model, producing concepts such disease outbreaks
Figure 1-6 n The One Health Initiative logo. (From B. Kaplan, http://www.onehealthinitiative.com.)
6 Human-animal medicine
3. Ensure functioning national emergency response capacity book provides numerous practical suggestions for helping
as well as a global rapid response support capacity such professionals retool and implement One Health con-
4. Promote interagency and cross-sectoral collaboration and cepts into their daily practice routines, which could enhance
partnership the preventive and therapeutic care they provide and lead to
5. Control highly pathogenic avian influenza and other further convergence between the disciplines.
existing and potentially re-emerging infectious diseases
6. Conduct strategic research
references
Research approaches linking human and animal health in
a One Health model hold great promise. Improved vaccine 1. Woolhouse ME, Gowtage-Sequeria S. Host range and emerging and
development and delivery for animal diseases such as brucel- reemerging pathogens. Emerg Infect Dis. 2005;11(12):1842–1847.
losis and avian influenza may reduce human risk from these 2. Chomel BB, Belotto A, Meslin FX. Wildlife, exotic pets, and emerging
zoonoses. Emerg Infect Dis. 2007;13(1):6–11.
diseases. Conversely, the conservation of great apes in Africa,
3. Wolfe ND, Daszak P, Kilpatrick AM, et al. Bushmeat hunting, defor-
currently affected by outbreaks of Ebola virus, could ben- estation, and prediction of zoonoses emergence. Emerg Infect Dis.
efit if a human vaccine were developed. Similarly, pharma- 2005;11(12):1822–1827.
ceutical developments and sustainable environmental health 4. Patz JA, Daszak P, Tabor GM, et al. Unhealthy landscapes: policy
recommendations on land use change and infectious disease emergence.
practices often have benefits across species.
Environ Health Perspect. 2004;112(10):1092–1098.
The Human Genome Project has resulted in the avail-
5. Wakefield J. Fighting obesity through the built environment. Environ
ability of sequencing the genomes of multiple animal species Health Perspect. 2004;112(11):A616–A618.
and an understanding of epigenetics. These molecular tools 6. Carson R. Silent spring. Boston: Houghton Mifflin; 1962.
are helping define the similarities and differences between 7. Bureau of Labor Statistics, U.S. Department of Labor. Occupational out-
look handbook, 2008-09 edition. http://www. bl.gov/oco/ocos076.htm.
species with regard to host-environment interactions as well
Accessed August 26, 2008.
as drug pharmacodynamics and pharmacokinetics. 8. National Research Council, Committee on the National Needs for
Disease surveillance represents another area of improved Research in Veterinary Science. Critical needs for research in veterinary
collaboration between human and animal health. Improved science. Washington, DC: National Academies Press; 2005.
9. King LJ. Personal communication. 2008.
early warning systems for disease risk that use both human
10. Grant S, Olsen LW. Preventing zoonotic diseases in immunocompromised
and animal data could help highlight environmental factors
persons: the role of physicians and veterinarians. EID. 1999;5(1):159–163.
driving disease outbreaks in wildlife, domestic animals, and 11. Kahn LH, Kaplan B, Steele JH. Confronting zoonoses through closer
human beings, leading to better disease prevention. collaboration between medicine and veterinary medicine (as “one med-
A better understanding of disease ecology and the impact icine”). Veterinaria Italiana. 2007;43(1):5–19.
12. Schwabe CW. Veterinary medicine and human health, ed. 3. Baltimore:
of environmental change on disease risk for both animals
Williams & Wilkins; 1984.
and human beings is essential to the One Health approach. 13. Aguirre AA, Ostfeld RS, Tabor GM, et al. Conservation medicine: ecologi-
As clinicians become increasingly aware that the diseases cal health in practice. New York: Oxford University Press; 2002.
observed in their human and animal patients are related to 14. Wilcox B, Kueffer C. Transdisciplinarity in EcoHealth: status and future
prospects. EcoHealth. 2008;5(1):1–3.
shared environmental health risks, this can create synergy in
15. Wildlife Conservation Society. The Manhattan principles on “One World-
collaboration with environmental health and disease ecology
One Health.” http://www.oneworldonehealth.org/index.html. Accessed
experts to reduce such risks. August 11, 2008.
In the midst of such developments, human and animal 16. Kahn LH, Kaplan B, Monath TP, et al. Teaching “one medicine, one
health professionals working on the front lines of clinical health.” Am J Med. 2008;121(3):169–170.
17. King LJ, Anderson LR, Blackmore CG, et al. Executive summary of
and public health practice will play an important role in the
the AVMA one health initiative task force report. J Am Vet Med Assoc.
recognition and management of a wide range of health issues 2008;233(2):259–261.
involving overlaps between human and animal health. This
2
Legal and Ethical Issues
in Human-Animal
Medicine
Peter M. Rabinowitz and Lisa A. Conti
The concept of increasing communication and collaboration • Do not treat animals or give veterinary medical advice
among public health, human health, and animal health pro- because these activities fall outside the scope of prac-
fessionals in a One Health model has numerous advantages. tice for human medical licensure.
Important legal and ethical issues apply to such professional • Provide medical services that promote public health,
interactions. Clinicians and public health professionals need such as preventive care for zoonotic disease.
to be aware that such issues can be complex and are continu-
ing to evolve. This chapter outlines some of these issues.
Veterinary Clinicians
Health care providers should query local authorities such
as health department attorneys, risk managers, and their • Comply with the state’s scope of veterinary practice.
professional associations about state and local regulations. • Counsel clients about zoonotic disease risks and how to
Although some international disease reporting requirements reduce such risks. Document in the veterinary medical
apply to animal and human health in the United States, pro- record all public health advice given to clients.
fessionals in other countries also will need to be informed • Provide clients with written information on zoonotic
about country and region-specific regulations. and other animal-related disease risks (such as the
CDC Pets-Scription), including advice about seeking
medical care if clinical signs develop.
Key Points for Clinicians and Public Health
• Provide competent preventive care for zoonotic dis-
Professionals
ease prevention.
• If clients decline preventive, diagnostic, or treatment ser-
vices for their animals for zoonotic disease, request that
Public Health Professionals
they sign a waiver documenting refusal of these services.
• Educate human health and veterinary clinicians about • Avoid giving human medical advice but offer to assist
requirements for reporting certain diseases to public in communication with physicians or other human
health authorities. health care providers regarding zoonotic or other ani-
• Facilitate communication between animal and mal-related health risks.
human health professionals while protecting patient • Request permission of client before discussing the cli-
confidentiality. ent’s animals with human health care providers.
• Respect the confidentiality of client medical informa-
tion and do not include protected health information
Human Health Clinicians
(PHI) about clients and their families in a veterinary
• Report notifiable diseases to public health authorities. medical record.
• Become knowledgeable about zoonotic and other • Report suspected animal abuse to appropriate authorities.
animal-related disease risks. Competently assess such • Provide veterinary medical services that promote pub-
risks during the care of patients. lic health, such as strategic deworming and vaccina-
• Provide written information on zoonotic and other tion against zoonotic diseases.
animal-related disease risks (such as the CDC’s Pets-
Scription: http://www.cdc.gov/healthypets/health_
prof.htm#petscription) to patients with animal LegaL considerations
contact. Information if include advice about seeking
medical care if symptoms develop. The convergence of animal health and human health
• Respect patient confidentiality when communicating described in Chapter 1 raises a number of potentially
with veterinary professionals and abide by applicable important legal issues of which human health and veterinary
laws and professional guidelines. providers should be aware.
7
8 Human-animal Medicine
scope of Practice
BOX 2-1 DEFINITION OF THE “PRACTICE OF
In some instances, physicians have been asked to treat ani- VETERINARY MEDICINE” FROM THE AVMA
mals belonging to their patients. Likewise, veterinarians have MODEL
been asked to treat people or provide medical advice and/
or medications that could be used for human beings as well
as other animals, especially when dealing with zoonotic dis-
eases. Both human and veterinary health professionals need
to be aware of the concept of professional scope of practice
and the need not to overstep professional bounds in such
situations.
Physicians and other human health care providers, includ-
ing nurse practitioners and physician assistants, are licensed
to evaluate and treat diseases in human beings. Individuals
without such licenses who provide medical treatment (such
as administration of prescription medication or performing
a surgical procedure such as suturing a wound) are “practic-
ing medicine without a license,” which is a violation of state
professional licensing (and possibly criminal) statutes. The
justification for licensing professionals is in part to ensure
they are appropriately qualified and can provide necessary
care. The exact scope of practice of physicians and other
medical professionals is determined by medical examining
boards of individual states and therefore can vary among
states. For example, licensed psychologists have the authority
to prescribe medications in some states but not in many oth-
ers.1 Obviously, the scope of practice for medical care provid- From American Veterinary Medical Association: Model Veterinary Practice Act, http://
ers does not include providing veterinary care for animals. www.avma.org/issues/policy/mvpa.asp.
Similarly, veterinarians are licensed to evaluate and treat
animals other than human beings. Veterinary practice acts
in different states define the practice of veterinary medicine BOX 2-2 VETERINARIAN’S OATH
and the scope of practice for veterinary professionals in that
state, including veterinarians and associated providers such
as veterinary technicians. Someone who diagnoses and treats
an animal (other than one he or she owns) without such
licensing is at risk of being charged with “practicing veteri-
nary medicine without a license.” The American Veterinary
Medical Association (AVMA) publishes a Model Veterinary
Practice Act (MVPA) that has been used by some states in
drafting scope of practice legislation.2 Veterinary providers
should be aware of their state’s current definition of veteri-
nary medicine and scope of veterinary practice. The defini- From http://www.avma.org/careforanimals/animatedjourneys/aboutvets/aboutvets.asp.
tion of veterinary practice in the MVPA is shown in Box 2-1.
of a veterinarian to perform such activities could potentially
lead to legal liability (see below). Veterinarians consequently
Veterinary Practice act
must carefully consider ways to fulfill their public health
As shown in Box 2-1, the “rendering of advice or recommen- obligations while not exceeding their professional scope of
dation” about animal diseases is part of the practice of vet- practice.3
erinary medicine, and this should be kept in mind by human
health care providers who are discussing animal health issues
Malpractice Liability
with their patients. The MVPA does not include any provi-
sions for veterinarians offering medical advice to their clients Both physicians and veterinarians are liable for malprac-
regarding human diseases. However, in addition, the oath of tice (damages awarded for professional negligence). Many
practice that veterinarians take when entering the profes- human health and veterinary providers carry malpractice
sion (Box 2-2) includes a commitment to “the promotion insurance, but such insurance covers only activities within
of public health, and the advancement of medical knowl- the scope of practice for that professional.
edge.” Therefore counseling clients about reducing zoonotic There is a growing realization of particular risks to both
disease risk, providing preventive care to reduce such risk, human and veterinary medical providers related to zoonotic
and notifying public health departments in a timely manner diseases in terms of malpractice liability related to human-
about human health risks would appear to be an intrinsic animal medicine issues, although legal precedent in this area
part of good preventive veterinary care. Failure on the part remains sparse. There is potential malpractice liability for
Chapter 2 n Legal and ethical issues in Human-animal Medicine 9
physicians and other human health care providers who fail to Management techniques to avoid these malpractice liabil-
correctly diagnose an animal-related disease such as a zoono- ities include the following:
sis in their patients because they failed to take an adequate his-
1. Educating clients about the risks of zoonotic disease
tory of animal exposures or otherwise consider the diagnosis.
and methods to reduce such risks, and documenting
For example, a physician who fails to obtain a history of bird
such education. To supplement such teaching, hand-
contact in the household and consequently fails to correctly
outs about zoonotic disease risks can be given to clients
diagnose a disease such as psittacosis in a person who shares
by veterinarians to educate them. An example of such
the household with the bird could be at risk of being sued for
a handout is the “Pet-Scription” and “Pet-Scription for
negligence (see Chapter 9). Management of this liability can
Reptile Owners” available from the CDC Healthy Pets
include training for physicians and other medical providers
Healthy People website. Discussions about zoonotic
in the recognition of zoonotic disease risk and other animal-
disease risk should be documented in the veterinary
related risks.
medical record.
Veterinarians are in a knowledgeable position to warn cli-
2. Asking clients who decline preventive treatment (such
ents about the risks of zoonoses and control the risk to human
as routine deworming) for their animals to sign a waiver
beings by competently managing disease in the animal popu-
documenting the refusal of such treatment. Examples
lation. Consequently, there appear to be a number of areas of
of such legal consent forms are available, but veterinari-
potential malpractice liability for veterinarians related to neg-
ans should seek advice from a local attorney about such
ligence in the management of zoonotic disease.
documentation because local statutes may vary.3
The first area of potential negligence is the failure to cor-
3. Increasing direct professional communication between
rectly diagnose a zoonotic disease in an animal. For example,
human health care providers and veterinarians. Direct
if a veterinarian fails to detect dermatophytosis in a cat used
physician-veterinarian contact offers several advan-
for animal therapy (see Chapter 5) and an immunocompro-
tages, including ensuring that diagnostic and thera-
mised person who is in contact with the cat becomes infected
peutic information is accurately conveyed, learning of
with Microsporum as a result (see Chapter 9), the veterinarian
other animal-human interaction health concerns, and
could be blamed for failing to diagnose the zoonotic risk. In
increasing dual awareness on the part of both types of
the past, it may have been more difficult to definitively link
practitioners about the health issues related to animal-
an animal infection to a subsequent infection in a human,
human contacts. Many sections of this book contain
but the use of molecular techniques to characterize particu-
specific suggestions for the content of direct commu-
lar strains of an organism crossing from animals to human
nication between human and animal professionals.
beings now allows such causative linkages to be made. Such
Such communications, however, need to consider con-
evidence could surface in a medicolegal setting.3
cerns about patient confidentiality (see below).
Another area of malpractice liability for veterinarians
related to zoonotic disease is the failure to recommend
preventive measures for common zoonotic diseases. This
Workers’ compensation Liability
situation could occur if a veterinarian failed to isolate an
unvaccinated stray cat with bite wounds with the subsequent Employers of animal workers, including owners of vet-
need for rabies postexposure prophylaxis among human erinary practices, zoos, and animal care facilities, are lia-
contacts if the cat develops rabies (see Chapter 9). In such a ble for work-related diseases in employees as a result of
case, the veterinarian could be held liable for not taking steps human-animal contact. Examples of potentially compens-
to control the zoonotic risk. Another example would be if a able diseases in animal workers include skin rashes, asthma
veterinarian diagnosed leptospirosis in a dog, failed to ade- or other allergy, animal bites, and zoonotic infections as
quately warn the owner regarding the zoonotic risk of dis- well as diseases resulting from exposure to anesthetic gases,
ease, and leptospirosis that could be traced back to the strain cleaning agents, and workplace noise. Incidents of work-
that infected the dog later develops in the owner. related injury and illness are compensable under state
In the case of exotic and wildlife pets that could harbor workers’ compensation statutes, with the employee being
unusual zoonotic diseases (such as monkeypox) or pose enven- potentially eligible for reimbursement of medical expenses,
omation risks (such as venomous reptiles), a veterinarian could lost work time, and other awards related to the illness or
be held liable for not warning clients about the dangers of keep- injury. Veterinarians and other employers of animal work-
ing such animals. Even in the case of rare and unusual zoonoses ers can manage liability for work-related illness and injury
and other disease risks related to exotic pets with which a vet- by taking steps to reduce risks in the workplace through
erinarian may be less familiar, it could be argued that the engineering and work practice controls for biological,
veterinarian should have referred the owner to a specialist for chemical, physical, and psychosocial hazards and by ensur-
diagnosis or treatment of a species or condition that was not ing the provision of adequate occupational health services
within the practitioner’s expertise (see Chapter 10). 3 for such workers (see Chapter 12).
An additional potential area of veterinarian malpractice
liability involves a failure to advise a client to seek care from
other Liability
a physician for diagnosis and treatment of a zoonotic disease.
This could occur if a client reports certain symptoms such as Veterinarians may be liable for physical injury to a human
fever or diarrhea to a veterinarian after an exposure to a sick (such as a dog bite) if it could be shown that the veterinarian
animal and the veterinarian fails to counsel that person to failed to properly counsel owners about ways to reduce the
seek medical care. risk of such injury and failed to intervene appropriately in
10 Human-animal Medicine
the care of a potentially dangerous animal. Again, educating notification and reporting
owners about warning signs of behavioral problems in dogs
Both human health care and veterinary providers are required
and other animals and steps to take to reduce risks of aggres-
by state and federal regulations to report certain diseases and
sive animals, and documentation of such education, is one
conditions to the appropriate health agencies, although the
way to manage liability.
lists of reportable human and animal diseases have areas of
overlap and some differences (see Chapter 13 for a listing of
confidentiality and the Health insurance nationally notifiable human and animal diseases). Whereas
Portability and accountability act human health providers must report notifiable diseases to
public health authorities, veterinarians may need to report
The Health Insurance Portability and Accountability Act animal and other diseases to agriculture departments, public
(HIPAA, known as the Privacy Rule) has tightened the rules health departments, or both (see Chapter 13).
regarding the release and sharing of personal health informa- In addition to reportable diseases, other medical condi-
tion (PHI) by medical providers treating patients. This rule tions require notification by health professionals. Human
also applies to health plans and health care clearinghouses.4 health care providers are required to report cases of sus-
PHI refers to health information that can be linked to an pected child abuse. Similarly, in some states veterinarians are
identifiable individual and that relates to the following: required to report suspected animal abuse (see Chapter 5).8
If human health care providers, veterinary providers,
1. Past, present, or future physical or mental health or
or their employees incur an occupational injury or ill-
condition of the individual
ness, including animal bites and zoonotic or allergic dis-
2. Provision of health care to the individual
ease among workers in an animal hospital or other animal
3. Payment for the provision of health care to the individual
care facility, such incidents need to be recorded on the
“Covered entities” under HIPAA include persons, busi- Occupational Safety and Health Administration (OSHA)
nesses, or agencies that furnish, bill, or receive payment for reporting log of work-related injuries and illnesses for
health care in the normal course of business.5 The Privacy that facility (see Chapter 12). Instructions regarding
Rule does not directly address confidentiality in veterinary OSHA reporting can be found at http://www.osha.gov/
practices. Provisions of the Privacy Rule allow PHI to be doc/outreachtraining/ htmlfiles/cfr1904.html.
released to public health authorities for the purpose of sur-
veillance and disease control. However, public health author-
ities must take steps to preserve the confidentiality of such
etHicaL issues
information.6
Veterinarians also have laws that govern the confiden-
tiality of veterinarian-client interactions.7 In some states, Professionalism
veterinarians are forbidden to release details regarding
One set of ethical issues concerns professionalism and expec-
the treatment of an animal without the written permis-
tations of practitioners. For example, patients have an expec-
sion of the animal’s owner. Although exceptions allow
tation that health care providers are honest and truthful, are
for communications between veterinarians or between
knowledgeable and current in their field, and act in the best
veterinarians and human health professionals or animal
interests of their patients. The idea that professionals act in
control officers, in general veterinarians should obtain
the best interests of their patients is both a legal and ethi-
the permission of their clients before releasing informa-
cal obligation known as a fiduciary duty. This duty refers to
tion about an animal’s diagnosis and treatment.7 HIPAA
the relationship of trust or confidence between professionals
legislation does not specifically mention veterinarians,
and their patients or clients. Professionals are expected to be
but some communications of health information between
loyal, not put personal interests above those of the patient or
veterinarians and human health care providers could
client, and not profit from the relationship unless the patient
involve HIPAA-defined PHI (see Chapter 3). For exam-
or client consents. An implication of this last point is the
ple, if a client mentions to the veterinarian that he or she
expectation that professionals minimize and disclose con-
has a medical condition that could predispose others to
flicts of interests.
zoonotic infection (see Chapter 10), such information
could be considered PHI.
Guidelines for practice in this environment for veterinar- ethical Principles in Human Health
ians include the following:
Another set of issues concerns ethical principles regard-
• Excluding identifiable health information about clients ing the conduct of human medical and veterinary practice.
or other persons in the household that could be consid- These can be characterized in ethical codes, in general prin-
ered PHI from the veterinary record (see Chapter 3) ciples, or by reference to cases (cases of good behavior and
• Refusing to provide medical advice to human beings cases of nonoptimal behavior). Because a profession may
(see also the scope of practice discussion above) have more than one code of ethics (for example, there are a
• Offering assistance to speak with the person’s physi- number of codes in medicine, some tailored to the particular
cian, with the person’s permission practice specialty), one broad approach to ethics is to iden-
• Educating the physician or other human health care tify and analyze practice using general ethical principles. In
provider on questions he or she may have regarding medicine there is widespread agreement on three principles:
pets, zoonoses, and pet care respect for persons (autonomy), beneficence, and justice.9