California’s horse owners are being urged to make sure their animals are vaccinated. Last year in Stanislaus County 46 horses contracted WNV, the highest number among all counties. The total for all California cases of equine WNV was 456, and 200 of them died (a case fatality ratio of 44%). In the great majority of these cases the horses either were not vaccinated or were vaccinated improperly. So far this year, all of the equine West Nile Virus cases in the immediate area have been in non-vaccinated horses.

“It is very important to ensure that all horses are solidly protected against West Nile Virus prior to the mosquito season, “ stated Dr. Dan Rolfe, veterinarian of the California. Department of Food and Agriculture, Animal Health Branch of the Modesto District. “Even at this time, when infected mosquitoes are known to be in the area, it is not too late to vaccinate. Call your equine veterinarian to have this done. A horse is a major investment in dollars and time, as well as a wonderful companion, or a working partner. It would be a shame to loose one just because of a mosquito bite.”

Signs of West Nile virus in horses include stumbling, staggering, wobbling, weakness, muscle twitching and inability to stand. Prompt veterinary treatment may decrease the severity of the disease, or might save the horse’s life. Horses contract the disease from carrier mosquitoes and are not contagious to other horses or people.

Confirmation of equine WNV cases serve as an important resource in protecting the public, and informing them of higher-risk geographic areas, as well as informing the mosquito control districts of problem areas, since most equine cases are contracted at their home.

“Mosquitoes have a range of travel of one mile or less,” said Jerry Davis, the Turlock Mosquito Abatement District Manager. “When a horse in an enclosed pasture is infected, it gives us a clear idea of the WNV risk that is present in the mosquitoes nearby. Birds can travel for miles in a day, so while they help us to gauge the prevalence of WNV it doesn’t clearly pinpoint where the contraction of the disease actually occurred.”

More information is also available to the public at www.stanemergency.com. Visitors can view a variety of maps showing information on mosquito pools, dead birds, and horses that have been confirmed to have WNV. This information is also available for the entire state at www.westnile.ca.gov.

Report mosquito infestations to the East Side Mosquito Abatement District at (209) 522-4098 or the Turlock Mosquito Abatement District at (209) 634-1234. The State of California is still requesting that residents of Stanislaus County report dead birds to the state hotline at 1-877-WNV-BIRD. Birds of particular interest to the state are crows, ravens, magpies, jays and raptors (hawk or eagle). The public may also submit the information via the web site www.westnile.ca.gov.