One Health for the Veterinary Team

In an age where multiple infectious diseases such as COVID-19 and monkeypox affect both humans and animals, and where significant environmental changes are linked more and more often to human activity, the concept of One Health has become increasingly more important. And the veterinary industry has been integral in advancing the visibility of One Health programs worldwide.

By Emily Singler

Stay Involved to Help Find Solutions

In an age where multiple infectious diseases such as COVID-19 and monkeypox affect both humans and animals, and where significant environmental changes are linked more and more often to human activity, the concept of One Health has become increasingly more important. According to the American Veterinary Medical Association (AVMA), One Health indicates that “humans, animals, and the world we live in are inextricably linked.”

As such, there must be a “collaborative effort of multiple disciplines working locally, nationally, and globally to attain optimal health for people, animals, and the environment.” To some, this may seem like common sense that humans would work to improve animal and environmental health for our own benefit, and indeed it is. Some of the ways in which this can be done, however, may not be so intuitive. And the central role of all members of the veterinary team in the success of One Health initiatives cannot be overstated.

The veterinary industry has been integral in advancing the visibility of One Health programs worldwide. In 2007, AVMA President Roger Mahr, DVM, established the One Health Initiative Task Force (OHITF). Ron Davis, MD, then president of the American Medical Association (AMA), oversaw approval of a resolution to “engage in a dialogue with the American Veterinary Medical Association to discuss strategies for enhancing collaboration between human and veterinary medical professions in medical education, clinical care, public health, and biomedical research.”

The American Public Health Association (APHA) then sent a liaison to join with those from the other two associations in the OHITF. The AVMA and multiple individual veterinarians continued to have an active role in the One Health Commission as it grew.

One Health Stories

Examples abound of how human, animal, and environmental health affect each other. Here are a few examples of particular interest to the veterinary community.

Sometimes, decisions made to treat animals can have significant implications for human health. In the 1990s, there was a public health crisis in India surrounding cattle, vultures, dogs, and humans. Cattle are raised in India for milk, for pulling carts and farm equipment, and for producing fertilizer. For the most part they are not slaughtered for any reason, because cultural and religious beliefs preclude most Indians from consuming beef.

Thus, cattle are allowed to die naturally and then left for vultures to scavenge after they die. In the late 1990s, there was a significant die-off in the number of vultures, which left many cow carcasses rotting in fields. Feral dogs seized the opportunity to scavenge this food source, and their populations ballooned.

The problem with this change was that these dogs were by and large not vaccinated for rabies. The subsequent rise in feral dogs was associated with over 39 million dog bites to humans and an estimated 48,000 rabies deaths in humans in the region. After an exhaustive investigation, the cause of the vulture die-off was determined to be diclofenac poisoning from consuming carcasses of cattle that had been treated with this anti-inflammatory drug.


Human disease and needs can also affect animal health and treatment. One such example is the current treatment climate for cats suffering from feline infectious peritonitis (FIP). Once considered a uniformly fatal disease of often very young cats, a new treatment option started gaining traction between 2016 and 2019. Named after its manufacturer Gilead Sciences, GS-441524 is an antiviral drug that works by preventing the formation of viral proteins. In experiments, this drug was found to be incredibly successful in curing cats diagnosed with FIP who would have otherwise died. Just when it seemed like the path might have been paved for approval of GS-441524 for treatment of FIP in cats, the COVID-19 pandemic hit. Because FIP and COVID-19 were both caused by (different) coronaviruses, it was found that both could be treated with similar drugs.

In fact, one of the drugs found to be most successful in treating COVID-19 in humans, remdesivir, is rapidly converted to GS-441524 in the body.Because of fears that production of GS-441524 for cats would hinder the production of remdesivir for critically ill humans, Gilead Sciences chose not to pursue approval of their drug for use in animals. Given the large need for the drug in cats, a new source of GS-441524, not approved for treatment of cats in the United States and many other countries, began to circulate from China.

Because veterinarians have been concerned about the legal implications of administering an unapproved drug, they have largely refrained from offering or even recommending it. As a result, desperate cat owners, breeders, rescuers, and others have developed their own network of distribution involving a Facebook page, unmarked vials, secret parking lot exchanges, and cat owners learning to give daily subcutaneous injections at home.

Animal and human health also contribute to and are affected by environmental changes around the world. The raising of food animals for meat for both humans and animals contributes to deforestation and increased production of carbon dioxide and methane, both of which contribute to global warming. It is estimated that meat production just to produce pet food creates about 64 million tons of carbon dioxide per year. Although eliminating meat in cat and dog diets is not likely to be a feasible solution, there are studies looking at the use of lab-grown meat and insects as more environmentally friendly options for protein sources in pet food in the future.


“Animal and human health also contribute to and are affected by environmental changes around the world.”


A recent JAVMA article identified factors that increase the risk of spread of leptospirosis among humans and animals. These factors include increased flooding due to more frequent and severe weather events, increased human travel and human encroachment on animal environments, and underrecognition of leptospirosis as a concern because of its nonspecific clinical signs and a presumption that it is limited to tropical climates.

Human medical practitioners, for example, may mistake leptospirosis signs as evidence of COVID-19. Veterinarians in certain parts of the country (and world) may also assume that the risk of leptospirosis is too low for their patients to recommend vaccination. However, leptospirosis cases have recently been identified in both humans and animals in areas of the southwestern United States where the climate is semiarid as opposed to tropical. This highlights the need for human and veterinary health professionals to share information on disease trends and to continue to learn how environmental changes can affect the health of their respective patients.

One Health in Veterinary Practice

Maria N. Donnelly, DVM, MSPH, has worked in both private practice and with the Florida Epidemic Intelligence Service Program (FL-EIS). She was drawn to a career in public health after growing up overseas in developing countries, and as she puts it, she “saw firsthand the impact of clean drinking water and a safe food supply make to people’s lives.”

Her master’s thesis project looked for changes in rates of posttraumatic stress disorder (PTSD) hospital visits (for humans) associated with increased wartime news coverage. She has also participated in emergency preparedness and response efforts and investigations of outbreaks (such as Clostridium botulinum, cryptosporidium, giardia, and others) at the county, state, and national levels.

Donnelly encourages all veterinary professionals to “become a part of organized veterinary medicine to stay informed with policy changes affecting One Health.” Apart from organized veterinary medicine, there are many ways that all members of the veterinary team can help improve and protect the health of animals, humans, and the environment.

Veterinary Support Professionals (VSPs)


Client service representatives, veterinary technicians, and veterinary assistants often have the first contact with an animal owner, whether over the phone, in person, or through a text or email. They are often the ones who experience the greatest emotions from a client: their fear or anxiety, their excitement and gratitude, or their anger. While clients wait to be called into an exam room or explain over the phone why they must change their appointment, VSPs may learn details of a client’s life, health, and challenges they are facing. They may be able to share some of this information with the rest of the team, when appropriate, to help personalize the care given to their animal.

Types of relevant information include their pet’s role as an assistance dog (service, therapy, or emotional support animal) and physical challenges of the owner that might interfere with their ability to follow through on treatment and lifestyle recommendations for their pets.

Physical challenges might include mobility concerns, trouble lifting, handling, or medicating their pet, or even trouble reading a medication label or opening a child-proof lid. If the owner volunteers that they or someone in their home are pregnant, immunosuppressed, or managing any number of different health conditions, this information may affect the types of recommendations, cautions, and even referrals for outside assistance that the team makes for this client.

Other helpful information can include financial constraints that can affect their ability to consent to recommended treatment, and even preconceived notions or misconceptions about their animal’s health and care. The veterinary team may be able to help resolve some of these obstacles if they know about them.

Apart from picking up on and relaying important information at the beginning of the appointment, VSPs will often be the last ones to see the client when they leave. They can help to repeat and reinforce recommendations made by the veterinarian, ensure that the client feels comfortable carrying out the treatment at home, and receive any feedback or last-minute questions from the owner. In some cases, the client will feel comfortable expressing thoughts and emotions to the VSP that they did not feel comfortable sharing with the veterinarian.


“The central role of all members of the veterinary team in the success of One Health initiatives cannot be overstated.”



As a veterinarian currently working in small animal private practice, Donnelly points out how she and her colleagues use their public health knowledge every day, and that it is “one of the most important aspects of our job.” This is evident in discussions of zoonotic transmission of intestinal parasites and prevention of dog bites in children.

Indeed, veterinarians recommend and prescribe treatment to protect human and environmental health in addition to improving the health of their patients. This can include vaccination for important zoonotic diseases, educating cat owners on the environmental effects of outdoor cats, and being responsible stewards of antibiotics to prevent resistance. Veterinarians can also highlight the power of the human-animal bond, for the benefit of both humans and animals.

Donnelly points to the US Centers for Disease Control and Prevention (CDC) slogan, “Healthy Pets, Healthy People,” as a great reminder of the connectedness between human and animal health. Veterinarians are uniquely qualified to understand the health risks of zoonotic diseases for both animals and humans. Although they cannot provide medical advice to their human clients, veterinarians can convince their clients of the importance of preventing zoonotic transmission and advise them when to seek appropriate medical treatment for themselves.

Apart from private practice, veterinarians work as pathologists, epidemiologists, researchers, and in a variety of government roles. In these capacities, they study trends in infectious diseases, protect our food supply, pioneer new treatments that can benefit both human and animal health, and ensure the safe transport of animals while reducing the risk of infectious disease transfer.

Further Reading:

One Health

A global one health perspective on leptospirosis in humans and animals

Our pets are part of the climate problem

One Health Commission

Diclofenac poisoning in vultures full/10.1111/j.0021-8901.2004.00954.x

Veterinary Social Workers

Veterinary Social Workers support the physical and mental health of veterinary team members and animal owners, which can give animals a better quality of life as well. They can work in veterinary hospitals, veterinary schools, animal shelters, programs for service and assistance animals, and anywhere that humans and animals interact. They can also help educate human healthcare professionals to properly assess their patients for eligibility for an emotional support animal, which can help support both physical and mental health in humans.

When asked about the most exciting advances in One Health recently, Donnelly pointed to the “increase in awareness of One Health as evidenced by more academic institutions with public health programs, increased education through the AVMA, and US and international government programs and policies focused on One Health.” This increased awareness shines a light on veterinary medicine and the important work that we do.

As we continue to work together with our fellow professionals, we can make a big difference in the lives of animals and humans, and in the health of the planet we call home. Perhaps more than anything else, this is a reason to keep learning, sharing, and innovating despite all the challenges we face in our profession.

Photo credits: ipopba/iStock via Getty Images Plus, ©Shannon Yahoudy, Searsie/iStock via Getty Images Plus, Lazy_Bear/iStock via Getty Images Plus, aldomurillo/E+ via Getty Images



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