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Colorado: Vesicular stomatitis cases confirmed in 35 counties

Christian Fernsby |
Cases of vesicular stomatitis (VSV) have been identified in 35 Colorado counties.

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Those are Adams, Alamosa, Arapahoe, Archuleta, Boulder, Broomfield, Chaffee, Conejos, Delta, Dolores, Douglas, Eagle, El Paso, Fremont, Garfield, Gilpin, Grand, Gunnison, Jefferson, La Plata, Larimer, Las Animas, Mesa, Mineral, Montezuma, Montrose, Morgan, Ouray, Park, Pueblo, Rio Blanco, San Miguel, Summit, Teller, and Weld. The total count of premises under quarantine for VSV by county is updated regularly on the CDA VSV website.

Two cows have tested positive for VSV on a small cow/calf operation in Larimer county. These cows had recently been brought down from summer pasture at a different location in Larimer county.

If VSV lesions are suspected, it should be reported to the state veterinarian’s office at 303-869-9130. All non-equine cases must be investigated by a state/federal veterinarian.

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.

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 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.

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