West Nile virus is transmitted to horses via bites from infected mosquitoes. | Photo: iStock

On Nov. 7 the Equine Disease Communication Center (EDCC) reported that the Ohio Department of Agriculture (ODA) has confirmed two more cases of equine West Nile virus (WNV). Officials have now confirmed 50 cases of WNV in Ohio horses so far this year—more than triple the number of cases confirmed last year.

According to the ODA and EDCC:

• A 7-year-old female donkey from Medina County developed hind-limb lameness on Oct. 16. A serum sample sent to USDA Animal and Plant Health Inspection Service’s (APHIS) National Veterinary Services Laboratory (NVSL), in Ames, Iowa, had an IgM capture ELISA positive at 1.400, suggesting recent WNV exposure. She is alive and recovering as of Oct. 26.
• An adult Belgian mare from Wyandot County was found by her owner down and unable to rise on Oct. 25. The attending veterinarian observed muscle fasciculation (involuntary twitching) on the mare’s face and neck and found that she had a fever of 102 degrees Fahrenheit. The veterinarian attempted treatment, but the owner eventually elected euthanasia due to the mare’s poor prognosis. The serum sample sent to Cornell University, in Ithaca, New York, had an IgM capture ELISA of 16.60 (>3.3=Positive), suggesting recent WNV exposure.

Neither the donkey nor the Belgian mare were vaccinated against WNV