Mosquitoes that feed on EEE-infected birds can transmit the virus to humans, horses, and other birds. | Photo: Photos.com

The three Jackson County (in south-central Michigan) horses tested positive for the virus on Oct. 4:

• An unvaccinated 5-year-old Quarter Horse mare that first showed clinical signs (lethargy and recumbency—down and unable to rise) on Sept. 26 and was euthanized.
• An unvaccinated 5-year-old Quarter Horse gelding that presented on Sept. 26, with clinical signs of recumbency and running in place while down. He was also euthanized.
• An unvaccinated 7-year-old Standardbred mare that began showing clinical signs Sept. 29. She was reported as deceased.

One horse from Kent County (in west-central Michigan), an unvaccinated 20-year-old Percheron gelding, presented on Sept. 29 with clinical signs that included decreased nerve function, inappetence, and lethargy. He succumbed to the disease on Oct. 2, and test results confirmed him positive on Oct. 4.

The final positive test result belonged to an unvaccinated 8-year-old Belgian gelding from Tuscola County (in east-central Michigan) that experienced onset of clinical signs, including fever, rapid back-and-forth eye movements, inability to stand, and paddling with his legs, on Sept. 29. He was subsequently euthanized and confirmed on Oct. 7