The United States Department of Agriculture’s Animal and Plant Inspection Service and the New Mexico Animal Health Authorities recently issued an alert to horse owners along the Mexican border, including Texas, that there have been active cases of Venezuelan Equine Encephalitis in Mexico.
Since rain fall amounts have increased recently, increased mosquito activity is making it a concern that this threat could cross the border into the United States.
At present, there is a quarantine of seven days on all equids crossing the border and a hold on certain products in the equine industry from entering the United States.
The Venezuelan strain has not been present in the U.S. since the early 1970s. It is in the family of arboviruses (arthropod-borne viruses) and includes Eastern and Western Equine Encephalitis.
Horses infected by mosquitoes can show signs of fever, lack of appetite, diarrhea, head pressing, circling, incoordination and blindness among other symptoms.
Incubation after a mosquito bite can be 2-4 days before symptoms occur and mortality can be as high as 90 percent.
Horse owners should consult with their equine veterinarian and consider vaccination for these viruses as well as West Nile Virus, which is also carried by mosquitoes before animals are exposed.
Booster vaccinations with the VEE virus may be encouraged at this time, since immunity is most likely not present unless this entity was included recently.
Conrad Nightingale practices at Hill Country Veterinary Hospital and Equine Center, Inc.