The Virginia Department of Agriculture and Consumer Services (VDACS) urges all horse owners to check with their veterinarians for West Nile Virus (WNV), Eastern Equine Encephalitis (EEE) and rabies vaccination recommendations for their animals.
Virginia only had one confirmed case of WNV in 2012 and no cases of EEE, although the number of horses affected in previous years and in other states was much higher.
State officials are concerned that horse owners may be lulled into inaction by the lack of diseases activity last year and neglect vaccination this year.
“We still urge horse owners to consider EEE and WNV vaccination.” says Dr. Charles Broaddus, Program Manager for VDACS’ Office of Veterinary Services. “We never know what mosquito activity will be in any given year, although with a wet winter and spring, it could be heavy in 2013. The bottom line is, these vaccines are very safe and effective. We believe that in most cases, private veterinarians will recommend them for their clients. Horse-owners need to be aware that the vaccines require boosters every six to twelve months.”
Dr. Broaddus added that VDACS is also suggesting that owners check about rabies vaccinations for their horses this year. “In the past few years, we have seen similar or greater numbers of cases of rabies in horses as WNV and EEE,” he said.
Vaccines are available to drastically reduce the incidence of WNV and EEE in horses. The vaccines are effective for six to twelve months, so horses should be re-vaccinated at least annually.
In areas where the disease occurs frequently, most veterinarians recommend vaccination every six months.
For the vaccine to be effective it must be handled and administered properly and be given at least two weeks before the horse is exposed to the virus. Additionally, to stimulate full immunity, horses must be vaccinated twice, about 30 days apart, the first year that the horse is vaccinated.
Other prevention methods include destroying standing water breeding sites for mosquitoes, using insect repellents and removing animals from mosquito-infested areas during peak biting times, usually dusk to dawn.
Rabies vaccines are also very effective and vaccinating horses annually can prevent rabies in both horses and humans. In addition to taking measures to decrease the likelihood that horses will be exposed to rabies, routine rabies vaccination is a very important aspect of disease prevention. Virginia typically reports 1-2 horses with rabies per year and last year reported 4.
All three of these diseases – EEE, WNV and rabies – cause neurologic signs in horses, such as staggering, circling, depression, loss of appetite and sometimes fever and blindness.
There is no cure for these diseases, which can kill anywhere from 30 percent (WNV) to 90 percent (EEE) to 100 percent (rabies) of the horses infected. Humans cannot become infected with EEE or WNV by handling an infected horse, nor can a horse acquire the virus from another infected horse; however, the presence of an infected horse in the area indicates that mosquitoes carrying EEE or WNV are present and those insects pose a threat to both humans and horses. Humans can become infected with rabies by handling a rabid horse.
For more information, contact the Office of Veterinary Services, Division of Animal Industry Services, VDACS, at 804.786.2483.