Eastern equine encephalitis (EEE) was found in two horses in Penobscot County, Maine, not long ago. An 18-year-old Miniature Horse mare that hadn’t been vaccinated tested positive on September 10 after showing severe neurological symptoms on September 3. She has since died.
Following severe neurologic signs on September 8, a Standardbred that had not been vaccinated enough tested positive on September 11. The horse was put down.
EDCC Health Watch is a marketing tool for Equine Network that uses data from the Equine Disease Communication Center (EDCC) to make and send out verified reports of equine diseases.
The EDCC is a separate, non-profit group that gets its money from gifts from businesses so that everyone can get information about infectious diseases.
EEE 101
Eastern equine encephalomyelitis is caused by the Eastern equine encephalitis virus, which most often lives in wild birds. People, horses, and other birds can get the EEE virus from mosquitoes that feed on sick birds.
Horses don’t get enough of these viruses in their blood for them to spread to people or other animals. In the United States, EEE is thought to be one of the most dangerous mosquito-borne diseases because it kills so many horses and people.
Some ways to avoid getting diseases spread by mosquitoes are:
- Avoid mosquito bites: Use insect repellent when outdoors, especially from dusk to dawn.
- Look for EPA-labeled products containing active ingredients such as DEET, picaridin (KBR3023), or oil of lemon eucalyptus (p-menthane 3,8-diol).
- Apply more repellent, according to label instructions, if mosquitoes start to bite.
- Mosquito-proof homes: Fix or install window and door screens, and cover or eliminate empty containers with standing water where mosquitoes can lay eggs.
- Protect your horses: Veterinarians recommend commercially available licensed vaccines against EEE for all horses in the U.S. Horses should be vaccinated at least annually (recommendations vary in high-risk areas). It’s not too late this year to vaccinate your horses.
- Use approved insect repellents to protect horses.
- If possible, put horses in stables, stalls, or barns during the prime mosquito exposure hours of dusk and dawn.
- Eliminate standing water, drain water troughs, and empty buckets at least weekly.
- Stock water tanks with fish that consume mosquito larvae (contact your local mosquito control for assistance), or use mosquito “dunks” (solid “donuts” of Bacillus thuringiensis israelensis, which are nontoxic to horses) available at hardware stores.