Vesicular Stomatitis Confirmed in Colorado

Vesicular Stomatitis. See large vesicle (bulla) on the dorsal snout. ( Iowa State University, College of Veterinary Medicine )

Colorado has become the third state in the U.S. to have a confirmed case of vesicular stomatitis (VSV).  On July 3, the National Veterinary Services Laboratory reported positive test results on samples submitted from two horses in Weld County that reside on separate locations. The horses have been placed under quarantine.  

Both premises in Colorado are private residences with horses as the only livestock species present, USDA Animal and Plant Health Inspection Service (APHIS) reported. One horse on one premises has met the case definition of infection with compatible clinical signs and positive complement fixation test titers at a greater than 1:40 dilution, which indicates recent infection. One horse on a second premises has tested polymerase chain reaction (PCR)-positive for VSV (Indiana serotype) on swaps collected from the lesions.

Previous positive cases of vesicular stomatitis in 2019 have been diagnosed in Kinney and Tom Green counties in Texas and in Sandoval County in New Mexico.  

What is Vesicular Stomatitis Virus? 
Vesicular stomatitis is a viral disease that primarily affects horses, cattle and swine. The agent that causes vesicular stomatitis, VSV, has a wide host range and can occasionally infect sheep and goats. In affected livestock, VSV causes blister-like lesions to form in the mouth and on the dental pad, tongue, lips, nostrils, hooves and teats. These blisters swell and break, leaving raw tissue that is so painful that infected animals generally refuse to eat and drink and show signs of lameness, APHIS said. Severe weight loss usually follows, and in dairy cows a severe drop in milk production commonly occurs. 

Humans may become infected when handling affected animals, but this is a rare event. To avoid human exposure, individuals should use personal protective measures when handling affected animals.

The USDA provides situation reports and information on the current VSV cases here. Additional information on VSV is also available.

Read more on VSV:
Vesicular Stomatitis, Anthrax Emerge in SW

Summer Brings Risk of Vesicular Stomatitis

Blister Diseases Causing Trouble for Pigs, Horses