ANNAPOLIS, MD –  As a result of heavy rains and increased mosquito populations, Maryland Department of Agriculture strongly encourages horse owners to make sure their equine friends are vaccinated against West Nile Virus and Eastern Equine Encephalomyelitis (EEE), two potentially fatal diseases that are spread by mosquitoes.

Horse owners who have vaccinated their horses against eastern equine encephalitis, western equine encephalitis and Venezuelan uine encephalitis still need to get their horses vaccinated for West Nile, as these are different viruses and those vaccinations do not provide cross protection.

“Preventing a disease is always less expensive and traumatic than treating it, so we urge horse owners to be proactive and vaccinate their horses now that mosquito season is in full swing,” said Maryland State Veterinarian Michael Radebaugh. “Your veterinarian is the best source of information and advice for your horse and its health.

We also remind veterinarians across the state that they must report any cases of equine arboviruses to the department.”

Signs of West Nile and EEE include fever (though not always with West Nile), anorexia, head pressing, depression or personality change, wobbling or staggering, weakness, blindness, convulsions, muscle spasms in the head and neck, or hind-limb weakness.

Horse owners can also help during mosquito season by keeping horses inside during dawn and dusk, which are peak mosquito times, and using topical insect repellents labeled for use on horses.

West Nile Virus is a serious and, at times, deadly disease that affects humans and horses. Both horses and humans can contract WNV and EEE if bitten by a mosquito carrying the virus, but the viruses cannot be transmitted between horses or from horses to people. The viruses normally exist in a cycle between mosquitoes and birds, but occasionally EEE can be transmitted from mosquitoes to mammals.

Because animals and humans both contract the virus from the bite of an infected mosquito, the department works closely with the Maryland Department of Health and Mental Hygiene every year to monitor virus activity in equines. Dogs and cats are generally not affected by West Nile. Veterinarians should use standard infection control precautions when caring for any animal suspected to have West Nile or any other viral disease.

Information about arboviral and other infectious diseases in equines can be obtained from the Animal Health section of the department’s website. For information on reducing mosquito breeding grounds. For more about the department’s mosquito control program.