Parts of the United States are currently experiencing a serious outbreak of illness associated with West Nile virus (WNV). Texas, one of the hardest hit areas, has over 600 confirmed human cases of West Nile this year, including 21 deaths. But West Nile virus doesn’t just affect humans; animals can be victims as well.
According to the American Academy of Equine Practitioners (AAEP), “Since 1999, over 25,000 cases of WNV encephalitis have been reported in U.S. horses. Horses represent 96.9% of all reported non-human mammalian cases of WNV disease. This virus has been identified in all of the continental United States, most of Canada, and Mexico.”
Clinical signs of West Nile encephalitis in horses include head tilt, muscle tremors, stumbling, lack of coordination, weakness of the limbs, or partial paralysis. There is no specific treatment for West Nile virus infections in horses other than symptomatic and supportive care. Approximately one-third of horses diagnosed with West Nile die from or are euthanized because of the disease. Some horses that survive the infection may suffer long-lasting neurological deficits as a result.
Dogs and Cats
Dogs and cats can also be infected with West Nile virus, but they rarely become sick from the exposure. Most individuals have such mild, minor, and short-lived symptoms (e.g., fever and lethargy), if they have any clinical signs at all, that their owners are never even aware that infection has occurred. Dogs and cats that have been diagnosed with West Nile virus infection do not pose a health risk to people.
How to Protect Yourself and Your Pets
According to the Texas Department of State Health Services, our best defense against being bitten by mosquitoes that potentially carry West Nile virus is to practice the “Four Ds”:
- Use insect repellent containing DEET, picaridin or oil of lemon or eucalyptus.
- Dress in long sleeves and long pants when you are outside.
- Stay indoors at dusk and dawn, when mosquitoes are most active.
- Drain standing water where mosquitoes breed. Common breeding sites include old tires, flowerpots, and clogged rain gutters.
These last two recommendations will protect your animals too, but don’t use human insect repellants on pets or products labeled for one species on another. Use mosquito repellent for horses, dogs or cats specifically.
A vaccine for West Nile is not available (or needed) for dogs and cats. On the other hand, the AAEP considers the West Nile vaccine to be a “core” vaccination, meaning that almost every horse should receive it. Don’t put your horse’s health at risk by skipping the West Nile Virus vaccine.