By Maegen Brown CVT, Oct 1 2018 04:52PM
This year West Nile Virus cases have been at an all-time high; likely due to our extremely rainy year. Almost every state has reported cases of the disease; horses represent 96.9% of all reported non-human mammalian cases. There is no treatment for WNV, your veterinarian can only treat the symptoms with NSAIDS and steroids to try and get the horse through the initial attack of the virus. The virus causes encephalitis (inflammation of the brain) or meningitis (inflammation of the lining of the brain and spinal cord). The fatality rate for horses exhibiting clinical signs of WNV is approximately 33%. Data showed that 40% of horses that survive the acute illness caused by WNV still exhibit residual effects, such as gait and behavioral abnormalities, 6-months post-diagnosis. Thus, vaccination for West Nile virus is recommended as a core vaccine and is an essential standard of care for all horses in North America. It is best to vaccinate in the spring, and then booster, depending on the climate, again in late summer/ early fall. WNV is most prevalent between May and October; these are the times that mosquito populations are high. Some signs to look for are: Fever, muscle twitching, stumbling, weakness or paralysis of hind limbs, impaired vision, ataxia, head pressing, aimless wandering, convulsions (seizures), inability to swallow, and hyper excitability. Most horses begin to show signs of the disease 3 to 15 days after being infected. Many horses will improve 5 to 7 days from the time they became symptomatic. If you see symptoms of WNV you should contact your veterinarian immediately; so they can begin treatment to better increase chances of survival and alleviate the horse’s discomfort. Possibly starting IV fluids or tube feedings if the horse is not eating or drinking enough. Not only is vaccinating important, but great lengths should be taken to try and remove standing water that creates an environment that mosquitoes thrive in. Also, most fly sprays also protect against mosquitoes.