A deer found in Hillsdale County last month tested positive for Eastern Equine Encephalitis, a disease carried by mosquitoes that’s particularly threatening for horses.

The recent Eastern Equine Encephalitis diagnosis could have a deadly effect on horses in Hillsdale County. Courtney Meyet | Courtesy

“It’s not terribly frequent, but it does occur and is something we know is a possibility in ruminant populations,” said Rebecca Burns, health officer at the Branch-Hillsdale-St. Joseph Community Health Agency.

The Michigan Department of Health and Human Services notified the agency the week of Oct. 13 of the diagnosis, which was the first EEE diagnosis in the county this year, Burns said.

According to the Michigan Emerging Diseases website, seven horses in Michigan have been diagnosed with EEE in 2017. There have been no cases of humans with the disease this year, although people are susceptible.

Those under the age of 15 and over the age of 50 are most vulnerable to the disease, but no more than 5 percent of human infections result in illness, which typically includes flu-like symptoms. Even fewer human cases are severe, and about a third of those are deadly, the website says.

For horses, EEE symptoms include loss of awareness, incoordination, lethargy, and muscle paralysis, Burns said. According to the Michigan Department of Agriculture and Rural Development, EEE fatality rates for horses ranges from 75 to 90 percent.

It’s common practice to vaccinate horses against the disease every year, said Assistant Professor of Chemistry Courtney Meyet. She said she’s not too concerned about the disease cropping up locally since she has vaccinated her five horses.

As the cold weather wards off mosquitoes, the disease is less of a threat, Meyet said, noting that it’s best to vaccinate horses in the spring. The high cost of vaccines probably deter some people from doing so, she added. She said she spends about $500 on a full set of vaccines for her horses.

Betsy Teetor, owner of Teetor Equestrian in Hillsdale, likewise said she wasn’t alarmed because she’s vaccinated her horses.

“I heard that it was found in a deer and made note of it. But I haven’t changed anything about my horse management or worried about it at all,” she said.

In general, that’s the attitude people should take, Burns said.

“People should not be overly worried, but it’s a good reminder for them to vaccinate their horses and take precautions for themselves,” Burns said.