Vesicular stomatitis confirmed

Veterinarians and Livestock Owners Contact:  Colorado State Veterinarian’s Office, 303-869-9130
By Mary Peck, 303-869-9005, [email protected]

For the first time since early July, cases of vesicular stomatitis have not been identified in any new Colorado counties. Cases are currently confirmed in the following 32 counties:

Adams, Alamosa, Arapahoe, Archuleta, Boulder, Broomfield, Chaffee, Conejos, Delta, Dolores, Douglas, El Paso, Fremont, Garfield, Gilpin, Grand, Gunnison, Jefferson, La Plata, Larimer, Mesa, Mineral, Montezuma, Montrose, Morgan, Ouray, Park, Pueblo, Rio Blanco, San Miguel, Summit, and Weld.

“The good news is that we have released 517 quarantines,” said Colorado State Veterinarian Dr. Keith Roehr. “That said, we still have 121 current quarantines in 26 counties and it is important to stay vigilant in fly control, monitoring horses and livestock for clinical signs, and reporting suspicious cases.”

ALL VSV cases are important for the epidemiology and management of this outbreak and MUST be reported to the State Veterinarian’s Office at 303-869-9130, regardless if the owner and veterinarian decide to have their livestock tested or choose to manage as positive premises based on the presence of typical clinical signs without testing. The only cases that may be managed as suspect positive are equine cases located in counties that have confirmed cases.

Equine owners and livestock producers across the state are impacted by VSV; all livestock owners should carefully watch the case numbers and affected counties to gauge their level of risk and institute mitigation measures.

The total count of premises under quarantine for VSV by county is updated regularly on the  CDA VSV website.

Please see the USDA APHIS Veterinary Services website to read the current situation report for all confirmed cases in the U.S.

The first case of VSV in Colorado was reported on July 3, 2019, in Weld County by a field veterinarian from the State Veterinarian’s Office at the Colorado Department of Agriculture.  An incursion of VSV-infected insect vectors is the likely source of infection. There are no USDA approved vaccines for VSV.

Vesicular Stomatitis Background

Vesicular stomatitis is a viral disease that primarily affects horses and cattle but occasionally swine, sheep, goats, llamas, and alpacas will show clinical signs. The transmission process of VSV is not completely understood, but includes insect vectors such as black flies, sand flies, and biting midges.

The incubation period ranges from 2-8 days. Clinical signs include vesicles, erosions, and sloughing of the skin on the muzzle, tongue, ears, teats, and coronary bands. Often excessive salivation is the first sign of disease, along with a reluctance to eat or drink. Lameness and weight loss may follow.

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.

Tips for Livestock Owners

• Strict fly control is an important factor to inhibit the transmission of the disease.

• Avoid transferring feeding equipment, cleaning tools or health care equipment from other herds.

• Colorado veterinarians and livestock owners should contact the state of destination when moving livestock interstate to ensure that all import requirements are met. Contact information for all state veterinarian offices is listed here.

• Colorado fairs, livestock exhibitions, and rodeos may institute new entry requirements based on the extent and severity of the current VS outbreak. Certificates of veterinary inspection (CVIs or health certificates) issued within 2-5 days prior to an event can be beneficial in reducing risks. Be sure to stay informed of any new livestock event requirements. See the Vesicular Stomatitis Guidelines for Shows and Fairs.

Important Points for Veterinarians and Horse Owners

Any vesicular disease of livestock is reportable to the State Veterinarian’s Office in Colorado – to report call 303-869-9130. If after hours, the voice message will indicate which staff veterinarian is on call.

Additional resources

• USDA APHIS Veterinary Services National VSV Update

• CDA Vesicular Stomatitis Information