Although the disease has not reached U.S. borders, vaccination is being strongly encouraged to protect horses in the U.S. and to provide a buffer of protection against spread of the disease. However, horses vaccinated for the disease may face severe export restrictions if intended for travel or sale outside of the United States. Available vaccines are very effective in protecting horses against the disease and are available in forms which allow for multiple protection, including Eastern and Western Equine Encephelomyelitis. VEE is a mosquito-borne viral disease of all equine species including horses, asses, donkeys and zebras. Although other animals such as cattle, swine and dogs can become infected, they generally do not show signs of the disease or contribute to its spread.
Humans can also contract the disease.
Healthy adults infected with the virus may experience symptoms such as high fever and headache. Those with weakened immune systems such as the young or elderly are more susceptible to VEE and may become severely ill or die. In 1993 and 1996, substantial outbreaks of Venezuelan Equine Encephalomyelitis were reported in the south of Mexico. The occurrence of these outbreaks in Mexico, coupled with a massive outbreak in Venezuela and Columbia in 1995, has prompted industry concern over the possibility that VEE might be reintroduced into the US horse population. VEE has not been diagnosed in the US since 1971.