Horses on a total of three sites in Texas and four premises in New Mexico are known to be infected with vesicular stomatitis (VS), a painful blistering disease of livestock such as horses, sheep, swine, and deer. The viral disease appears spontaneously and sporadically in the southwestern United States and is thought to be transmitted by sand flies and black flies. The VS cases this spring are the first to be confirmed since l998.
 
“The most recent confirmed cases in Texas involve three horses on a ranch near Denver City, in Yoakum County, about 80 miles southwest of Lubbock, and one horse near Del Rio, in Val Verde County about 150 miles west of San Antonio,” said Dr. Bob Hillman, Texas state veterinarian and head of the Texas Animal Health Commission (TAHC), the state’s livestock and poultry health regulatory agency. The country’s first VS cases this year were confirmed May 19, in three horses, which are confined to their ranch in Reeves County, in far west Texas.
 
To prevent animal-to-animal disease transmission, the TAHC requires that the VS-infected animals and the other livestock on the premise remain quarantined until 30 days after all VS blisters or lesions heal, a process that usually takes two or three weeks. Prior to quarantine release, the animals will be re-examined by a state or federal regulatory veterinarian, to prevent the spread of disease to other premises.

Dr. Steve England, state veterinarian for New Mexico, said a “handful” of horses on four small premises near Carlsbad, N.M., were found to be infected since June 4. The animals remain quarantined on their premises.
 
“During an active year for VS, it is not unusual for this unpredictable disease to be found scattered across several counties and states,” said Hillman. “We urge owners and private veterinary practitioners to report clinical signs of the disease to their state veteri