West Nile virus (WNV) first appeared in the United States in 1999, but it remains a serious horse health threat.

In 2016, there were 377 equine WNV cases across the United States—an increase of 152 cases from what veterinarians diagnosed in 2015. Horses are at the highest risk for contracting WNV during peak mosquito season, which typically occurs July through October in the United States. Fortunately it’s not too late to help protect horses against this devastating disease.

“Vaccination is extremely effective against West Nile virus and remains the most effective way to help protect horses against the disease, in conjunction with mosquito control,” said Kevin Hankins, DVM, MBA, senior equine technical services veterinarian for Zoetis.

When properly vaccinated, research has shown that horses can be 30 times less likely to contract WNV