Horses and humans are dead-end hosts for West Nile virus. In spite of the availability of effective vaccines, 2018 saw a rebound in the number of reported equine cases; the highest since 2012.
The peak season for infection is late September to October, but it can occur any time mosquitoes are present.
Source: Veterinary Medicine, August 3, 2019. Link. It’s up to veterinarians to educate horse owners that this vector-borne disease still poses a very real threat. West Nile is still endemic in much of the United States and should be considered a differential diagnosis for horses that present with acute onset of ataxia, depressed mentation and potentially a fever.
Highly effective vaccines are available, and it has been shown that unvaccinated animals are twice as likely to die as those that have been vaccinated even once. – Kate L. Hepworth-Warren, DVM, DACVIM
INSIGHTS: For every animal health pro who interacts with horse owners, equine veterinarians or farm retailers, this article is an absolute call to action. One can almost hear Hepworth-Warren saying, “Come on man!”