Wildlife veterinarians are natural one-health advocates as they work at the interface of human, animal, and environmental health. For insights into this line of work, AVMA News spoke with four wildlife veterinarians about their backgrounds and areas of expertise. This is the third article in our five-part series.

Wildlife disease as a frontier of discovery

Dr. Jonathan Sleeman is heading up an ad hoc committee for the American College of Zoological Medicine looking at ways to encourage more veterinarians to become diplomates in the ACZM discipline of wildlife population health. He is one of about a dozen diplomates in the discipline and center director of the U.S. Geological Survey’s National Wildlife Health Center, close to the campus of the University of Wisconsin-Madison.

The ACZM was established in 1983 and always has been a broad tent, Dr. Sleeman said. Diplomates include veterinarians in the disciplines of general zoo health, aquatic animal health, and the health of zoological companion animals—also known as exotic pets.

The discipline in wildlife population health involves epidemiology, outbreak investigation, and knowledge of wildlife diseases. It is designed to give veterinarians the skills to work in a variety of settings.

Dr. Susan Knowles, a wildlife pathologist with the U.S. Geological Survey’s National Wildlife Health Center, performs a necropsy of a juvenile whooping crane.

“We are seeing increasing impacts of diseases on wildlife populations,” Dr. Sleeman said. He said the National Wildlife Health Center, founded in the 1970s, did a lot of work on avian botulism and avian cholera, which could cause fairly large-scale outbreaks but didn’t usually threaten the existence of species.

Since the 1990s, the number of emerging diseases in wildlife has been ever increasing because of drivers such as climate change, habitat loss, and globalization, Dr. Sleeman said. Among these diseases are West Nile virus, highly pathogenic avian influenza, chronic wasting disease in cervids, white-nose syndrome in bats, and the SARS-CoV-2 virus in wildlife.

“We are just seeing an ever-increasing number of diseases, and these diseases are increasingly threatening the survival of species,” Dr. Sleeman said. Plus, they spread very rapidly over large distances.

These situations require more surveillance and the need to proactively manage and prevent these diseases. He said, “Veterinarians have the skills to do that work.”

When Dr. Sleeman started out in his native England, he earned a bachelor’s degree in zoology and then a veterinary degree in 1992, thinking he would combine his interest in wildlife and in medical sciences to become a wildlife veterinarian—not knowing the position was rare. Nevertheless, he went on to a residency in zoological medicine at the University of Tennessee, including studies with free-ranging wildlife.

“I enjoyed the work with wildlife. I found it very challenging just working with wildlife, and I enjoyed that challenge,” Dr. Sleeman said. “Scientifically, it is very interesting to me because it’s one of the frontiers of discovery. We know so little about diseases in wildlife populations and their implications and their impacts.”

He went on to hold positions with the Mountain Gorilla Veterinary Project in Rwanda, Colorado State University, and the Virginia Department of Game and Inland Fisheries. He became center director of the USGS National Wildlife Health Center in 2009.

David Blehert, PhD, of the National Wildlife Health Center; Dr. Craig Stephen of the Canadian Wildlife Health Cooperative; and Dr. Jonathan Sleeman of the NWHC visit the Thailand National Wildlife Health Center to initiate a World Organisation for Animal Health twinning project. (Courtesy of Dr. Sleeman)

The NWHC, with a new strategic plan that emphasizes a one-health approach, is looking at taking a systems approach to certain challenging wildlife diseases, Dr. Sleeman said. For example, habitat management potentially could improve the health of wildlife populations overall to increase their resilience to diseases.

The center received $5 million through the American Rescue Plan Act, one of the federal laws in response to the COVID-19 pandemic, to continue developing the Wildlife Health Information Sharing Partnership. The online system serves as a central repository of information on wildlife health.

The NWHC also is exploring how to apply new technology such as artificial intelligence to wildlife health data. Dr. Sleeman said much of the data is messy and nonstandardized. He said the hope is to provide early alerts and devise new solutions.

Another initiative is international engagement. The center is collaborating with the World Organisation for Animal Health to improve international information sharing on wildlife health, has made information cards on wildlife diseases for other countries, and helps other countries build capacity in wildlife health programs.

Just recently, the WOAH, along with the Food and Agriculture Organization of the United Nations, the United Nations’ Environment Programme, and the World Health Organization, launched the One Health Joint Plan of Action, to improve the health of humans, animals, plants, and the environment while contributing to sustainable development.

A version of this article appears in the January 2023 print issue of JAVMA.