Officials On Alert For African Horse Sickness

African horse sickness is not in the U.S., and it is important it stays that way. Texas A&M AgriLife faculty, various state and federal agencies and the U.S. horse industry are already monitoring the situation, ensuring surveillance and determining practices to prevent the deadly horse disease from crossing our borders. Horses would be at risk if African horse sickness makes it into the U.S. African horse sickness comes out of Africa and is common from Morocco down to the middle of the continent. But it has escaped the African continent several times, most recently into Thailand, where it is believed to have been introduced by importation of infected zebras. African horse sickness is caused by a virus, more specifically an Orbivirus, which is transmitted by certain insects. “Equines including horses, mules, donkeys and zebras are moved all over the world for competitions, trade, breeding, zoologic and conservation purposes,” said Pete Teel, Ph.D., Texas A&M AgriLife Research entomologist with the Texas A&M Department of Entomology, College Station. African horse sickness is considered a Tier 3 disease by the National Bio and Agro-Defense Facility, NBAF, because of the potential negative impact on animal health. African horse sickness symptoms are the same as those associated with respiratory and circulatory impairment. At the first signs of the disease, owners are advised to eliminate affected horses and vaccinate noninfected horses with polyvalent vaccine; then let them rest for two weeks. The APHIS and the U.S. Fish and Wildlife Service have import requirements in place to reduce the likelihood of AHSV introduction. Per APHIS regulation, imported horses undergo inspection prior to export. Horses imported from AHS-affected countries are required to undergo a 60-day quarantine upon arrival in the U.S. Horses are the most susceptible host with close to 90% mortality of those affected, followed by mules and donkeys. African donkeys and zebras very rarely display clinical symptoms, despite high virus titers in blood, and are thought to be the natural reservoir of the virus. Thus, it is thought the virus was transported to Thailand through asymptomatic zebras...MORE