A large mosquito infestation is expected in Kentucky this year after a rainy spring. Mosquitoes can carry West Nile virus (WNV), so the commonwealth’s agriculture commissioner, Richie Farmer, is encouraging horse owners to talk to their veterinarians about vaccinating their horses for the virus.

The WNV vaccine has become a part of many horse owners’ core annual vaccine schedule.

"Since 2003, no horses known to have been properly vaccinated have gotten West Nile in Kentucky," Farmer said. "Kentucky had 513 equine cases of West Nile in 2002–the first full year the virus was active in Kentucky–and 137 horses died. Since then, vaccination has become much more common, and the number of cases of West Nile has fallen sharply."

Historically in Kentucky, WNV starts being identified in horses in July. The number of cases usually increases throughout the summer before peaking in mid-September. WNV was first identified in Kentucky’s equine population in the fall of 2001. A total of 683 horses have been diagnosed with the disease in Kentucky in the past 10 years