A cow infected with epizootic hemorrhagic disease has been detected in eastern Wyoming near Lusk.
The cow was off-feed and drooling and had vesicular lesions in its mouth — all symptoms of EHD, according to a press release from the Wyoming Livestock Board.
Samples from the cow were sent to the U.S. Department of Agriculture’s National Veterinary Services Laboratory. The lab confirmed Wednesday it was EHD.
The infected cow is in isolation and is now being treated, said State Veterinarian Dr. Jim Logan.
EHD is a viral disease that typically infects deer but during drought conditions it has been known to infect cattle, Logan said.
The disease is passed along by gnats, which congregate by water. When drought conditions force more animals to congregate around scarce water sources, it creates more chances for livestock to be infected.
EHD has been found in deer in northeastern Wyoming recently and cases affecting both deer and cattle in the past few months have been reported in Nebraska, Colorado and South Dakota.
Aside from spraying their cattle with insecticide, which Logan said might sound easy but isn’t practical, ranchers should keep their cattle spread out when watering. The more spread out cattle are, the harder it would be for an infected gnat to bite multiple cattle.
While EHD is often fatal for deer, that isn’t the case for cattle. After being infected by the disease, cattle are usually able to fight off the virus. The main thing, Logan said, is to make sure the cow is hydrated. The lesions in an infected cow’s mouth make it painful to drink, Logan said.
It is extremely rare for the disease to spread from cow to cow, Logan said. Logan said a good “killing frost” would help kill gnats and take care of the problem.
“Once the gnats are gone, the likelihood of having any further spread or cases is very small,” Logan said.
Ranchers should not hesitate to call their veterinarian if they notice symptoms in their herds.