Diseases Prompt Caution from Wyoming State Veterinary Laboratory Director

Tularemia, plague, West Nile virus, rabies, vesicular stomatitis -- Wyoming State Veterinary Laboratory (WSVL) experts are cautioning residents to monitor not only their pets and livestock, but also themselves this summer.

The WSVL has diagnosed several cases of tularemia in wildlife and domestic animals, including in Albany, Platte and Washakie counties, says Will Laegreid, WSVL director.    

“There have been a number of human tularemia cases in Colorado this summer and two so far in Weston County, and we would like to prevent any more cases in Wyoming if possible,” he says. The Wyoming Department of Health reported the cases.

Caused by bacteria, tularemia -- also called rabbit fever -- is commonly associated with rabbits and rodents, he says, and outbreaks often coincide with booming rabbit populations, as seen in Wyoming this year.

“Tularemia may be quite serious in humans, who may become infected through direct contact with wild rabbits, prairie dogs, voles and other rodents through insect or tick bites or through ingestion of contaminated food or water,” Laegreid says.

Pets, especially cats, are susceptible and may be a source of infection for their owners, he says.

Laegreid advises avoiding contact with wild rabbits and rodents, especially those that appear ill, and keeping pets away from these animals. Other measures include using chemical insect repellents and dressing to avoid tick and deerfly bites, wearing gloves when dressing wild game, especially rabbits, and avoiding untreated water.

“It is worth noting that plague, another very serious disease, is present in Wyoming, closely resembles tularemia and shares many of the same risks for human and animal infections as tularemia,” he says. “Two fatal human plague infections have occurred this year in Colorado, highlighting the need for people to be aware and take actions to prevent these infections.”

The first detections of West Nile virus in birds and mosquitoes have been made in multiple Wyoming counties, Laegreid says.

“We expect West Nile will continue to increase until the onset of cooler weather. Vaccination of horses for West Nile virus and avoiding mosquito bites should reduce the chance of infection,” he notes.

Laegreid says rabies continues to be diagnosed in bats and skunks throughout Wyoming. Avoid them, especially if they are behaving abnormally. Ensure dogs and cats have up-to-date vaccinations.

Vesicular stomatitis (VS) has been diagnosed in horses in eastern Wyoming. Laegreid says the disease also may affect cattle, swine and humans.

While not fatal, VS causes severe blistering of the mouth, teats and coronary band of the hooves, he says.

Laegreid says VS is reportable because its symptoms are similar to foot-and-mouth disease. The WSVL has been activated as a member of the National Animal Health Monitoring System to diagnose VS cases in horses.

“Please contact your local veterinarian if your horses are drooling, refuse to eat, will not allow foals to nurse or turn up lame,” he says.

For Centers for Disease Control and Prevention information about these diseases:

Tularemia and plague -- www.cdc.gov/Tularemia; www.cdc.gov/plague.  

Rabies -- www.cdc.gov/features/dsrabies.

West Nile virus -- www.cdc.gov/westnile.

The American Association of Equine Practitioners has West Nile virus information pertinent to humans and horses -- www.aaep.org/info/west-nile-virus.

The Center for Food Security and Public Health at Iowa State University has a primer on VS, including images of its appearance in horses -- http://bit.ly/vesicularstomatitis.