Warning Signs

By Heather W. Barron, DVM, DABVP

Hospital Director, CROW


As the old adage goes, “for every single thing you miss by not knowing, you will miss ten things by not looking.” Well, at CROW, we are looking closely at the health of Southwest Florida’s wildlife. A big part of conservation medicine is appreciating the things that sick, wild animals may be trying to tell us about the health of our environment. Staying on the cutting edge of wildlife medicine and collaborating with human health officials, local biologists, and environmentalists allows us to best serve the One World, One Health concept.


<< Ranavirus is not harmful to humans but since turtles can expose people to other issues it is best to use a towel or some other barrier when picking up an animal deemed ill.<<

An excellent example of this are the annual outbreaks of ranavirus that have occurred within Florida Box Turtle populations in southwest Florida over the past few years. Ranaviruses have been called “cold-blooded killers” because they cause illness and death in cold-blooded wildlife such as fish, amphibians, and reptiles.


This emerging viral disease has rarely been documented in Florida reptiles, possibly because no one knowledgeable about the disease has been looking. When the first turtle with characteristic clinical signs, such as swollen eyelids, plaques in the mouth, and nasal discharge was admitted to CROW in 2013, our veterinarians were highly suspicious. State wildlife veterinarians were immediately alerted and samples were submitted to the Southeastern Cooperative Wildlife Disease Study (SCWDS), where the diagnosis was confirmed. Since then, we have documented outbreaks of ranavirus in Lee County box turtles every winter.


Ranavirus typically exists at low prevalence (less than 5 percent of individuals infected in a population), and then rapidly emerges, with mortality often exceeding 90 percent in multiple species. With one in three amphibian species and over 40 percent of turtles at risk of extinction, ranavirus represents a significant threat to their biodiversity. Ranaviral disease has been likened to Ebola virus for amphibians because their bodies swell and bleed profusely.


The reasons for ranavirus emergence at a site vary, but often are related to stressors that can be natural or anthropogenic (human-related). For example, outbreaks might signal that local ponds and wetlands are becoming more susceptible to disease under the stressors of climate change, pollution and development. In this sense, wildlife can serve as sentinel populations to give us early warnings when the environment is not healthy. It is essential that we understand the threat of ranavirus and act quickly to address its spread.


>>Visitors can learn about Florida Box Turtles and meet one in person at CROW’s new box turtle exhibit. The exhibit includes a Florida Box Turtle (pictured on right) and an Eastern Box Turtle.>>


Box turtles may live for a hundred years or more, but their populations are threatened by disease, habitat loss, vehicle strikes, and illegal collection. If you would like to learn more about box turtles, you can visit CROW’s Education Center Monday through Friday from 10 a.m. to 4 p.m. All proceeds from our Education Center and Gift Shop help us continue our mission to save wildlife through state-of-the-art veterinary care, research, education and conservation medicine.