Vesicular Stomatitis Detected in Texas; Kentucky Bans Livestock

Vesicular stomatitis (VS), a disease with international implications for animal movement because symptoms mimic those of foot and mouth disease, was confirmed May 19 in western Texas. In response to that announcement, Kentucky Department of Agriculture officials banned the import of Texas horses and other livestock until 30 days after the final case confirmation.

Horses, cattle, pigs, and occasionally sheep, goats, and deer are affected by VS, which causes blisters to form in the animal's mouth, on teats, or along the coronary band of hooves. These blisters result in excessive salivation, lameness, or oozing sores. VS clinical signs can generate considerable concern because they mimic those of the highly contagious foot and mouth disease, which hasn't been found in this country since 1929. Lab tests can differentiate between the two diseases. Unlike foot and mouth disease, VS can affect horses.

A safe, effective vaccine against VS is not currently available in the United States.

According to Max Coats, DVM, deputy director for Animal Health Programs for the Texas Animal Health Commission (TAHC), the state's livestock and poultry health regulatory agency, VS was confirmed in three horses on a ranch in Reeves County in western Texas that houses nine horses and nine steers. The disease was initially detected on May 10. The source of the disease is unknown--there was no history of recent herd additions or exposure to other animals, according to information from the USDA's Animal and Plant Health Inspection Service.

Arthropods such as ticks, mites, biting midges, mosquitoes, or house flies start a VS outbreak through transmission of the virus. Once an animal develops clinical signs (two to eight days after infection), the outbreak 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 herdmates. Sick animals must be isolated until they heal. The Reeves County ranch will be quarantined for several weeks until all animals are free of the disease.

Coats recommended that veterinarians and handlers wear rubber or latex gloves working with VS-infected animals and thoroughly wash their hands afterward. "Humans reportedly may contract VS and develop flu-like symptoms that can last four to seven days," he warned.

Prior livestock VS outbreaks occurred in 1982-83 (in an unspecified locale), 1995 (365 ranches infected in New Mexico, Colorado, Arizona, Utah, and Texas), and May 1997 (in Arizona, which eventually led to the infection of 380 ranches in Arizona, Colorado, New Mexico and Utah). The most recent confirmation of VS before this year was in 1998, in Reeves County and in New Mexico.

The ban of livestock from states with VS infection was passed into Kentucky legislation in 1995, according to Kentucky state veterinarian, Robert Stout, DVM. Once 30 days have passed after the diagnosis of the final VS case in Texas, Kentuckians will be permitted to resume importing Texas horses. The order also prohibits the entry into Kentucky of any such animals that have been in Texas in the previous 30 days. It requires equids coming into Kentucky from states that border Texas to have a negative VS test within the 30-day period preceding their entry into the Commonwealth. Approximately 2,099 head of livestock entered Kentucky from Texas last year (mostly cattle, horses, and goats).

"The whole livestock industry is affected by this," said Stout. "We realize that there are economic implications, but the protection of Kentucky's livestock industries from that disease, and from the international implications of having it, were the reason the regulation was put in place."

What if VS hit Kentucky? "I don't even want to think of it, it would be disastrous," said Stout. The Office International des Epizooties classifies VS in its list of "Class A" diseases, "Transmissible diseases that have the potential for very serious and rapid spread, irrespective of national borders, that are of serious socio-economic or public health consequence and that are of major importance in the international trade of animals and animal products." VS could pose a serious threat to the Kentucky horse industry because of the sheer volume of horses shipped internationally from the state.

Enforcement can be difficult for this type of ban, but Stout said, "We have strategically placed our investigative staff to try and monitor horses coming into Kentucky, as well as other livestock, and we're soliciting the aid of other law enforcement agencies in helping us with that surveillance." He emphasized, "Horses and livestock that are identified coming from Texas will be turned away."

Texas officials are encouraging livestock owners to report any suspicious clinical signs to the TAHC's hotline at 800/550-8242.

About the Author

Stephanie L. Church, Editor-in-Chief

Stephanie L. Church, Editor-in-Chief, received a B.A. in Journalism and Equestrian Studies from Averett College in Danville, Virginia. A Pony Club and 4-H graduate, her background is in eventing, and she is schooling her recently retired Thoroughbred racehorse, Happy, toward a career in that discipline. She also enjoys traveling, photography, cycling, and cooking in her free time.

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