July 15, 2004
July 15, 2004 -- The country's first case of Vesicular Stomatitis (VS) since 1998 was confirmed May 19, 2004, on a premise with nine horses and eight cattle in Reeves County, Texas.
VS is a viral disease that occurs sporadically in the United States, usually in southwestern states. The disease can affect horses, cattle and pigs, and occasionally, sheep, goats and deer, causing blisters to form in the animal's mouth, on teats or along the hooves, resulting in excessive salivation, lameness or oozing sores.
Researchers have determined that VS outbreaks are started by a virus transmitted by arthropods, such as ticks, mites, biting midges, mosquitoes and house flies. Following an incubation period of two to eight days, infected animals may develop clinical signs of the disease. The outbreak then can be perpetuated by biting insects that carry the disease from infected to healthy livestock.
VS-infected animals also can spread the virus if their saliva or the fluid from ruptured blisters contaminates equipment or feed shared by herd mates. Sick animals should be isolated until they are healed. VS is rarely fatal, and infection usually runs its course in a few weeks. Infected livestock may need supportive care to prevent secondary infections where blisters have ruptured.
As a biosecurity measure, ranchers and veterinarians should wear rubber or latex gloves when handling potentially infected animals, and wash their hands thoroughly afterward. Livestock that develop sores or erosions should be tested for VS as soon as possible. Infected animals should be quarantined until the illness has run its course.
The clinical signs of VS can cause concern because they mimic those of a highly contagious foreign animal infection, foot-and-mouth disease (FMD), which has been eradicated in the United States since 1929.
The only thing 'regular' about VS is its 'irregularity.' Thirteen years passed between a 1982-83 outbreak of VS and one in 1995 that involved infection on more than 365 ranches in five states -- New Mexico, Colorado, Arizona, Utah and Texas. In May 1997, the disease was detected in Arizona. By late fall, when the outbreak ended, infection had been detected on 380 ranches in Arizona, Colorado, New Mexico and Utah.
The National Veterinary Services Laboratory in Ames, Iowa, has confirmed that the three horses in Reeves County have VS. All livestock on the affected ranch will remain quarantined for several weeks, until they no longer pose a health threat to other livestock.