Virus season: Commonsense practices to keep your livestock healthy

two horses grazing, wearing fly sheets
Keep an eye on your livestock this summer to prevent Vesicular Stomatitis, a viral disease which primarily affects horses, cattle, and swine. Photo: Ragan Adams/College of Veterinary Medicine and Biomedical Sciences

Summer in Colorado is finally in full throttle, especially green and lush due to the wonderful moisture we received this spring. People owning commercial and non-commercial livestock (cattle, sheep, goats, swine, mules/donkeys, camelids and horses) are moving and mingling their animals with others at shows, fairs, rodeos, markets, on grazing allotments, and during normal recreation.

A few commonsense practices will decrease the chance your animals develop an infectious disease.

Just last month, Texas and New Mexico animal health officials announced that the Vesicular Stomatitis Virus (VSV) was confirmed at locations in their states.

Colorado is now the third state in the country to have a confirmed case of Vesicular Stomatitis Virus, according to the state Department of Agriculture’s Animal Health Division.  On July 3, the National Veterinary Services Laboratory reported positive test results on samples submitted from two horses in Weld County. The horses reside in separate locations and have been placed under quarantine.

See updated situation reports on the USDA’s Animal and Plant Health Inspection Service site.

The virus causes vesicular or blister-like lesions that lead to painful erosions and sloughing of skin on the muzzle, tongue, teats and above the hoof (the coronary band) of infected animals. Depending on where the lesions are located, animals may be lame or not want to eat or drink.

Horses, cattle and swine are most often affected but mules/donkeys, bison, sheep, goats and camelids are susceptible.

VSV is a reportable disease because it resembles foot and mouth disease and swine vesicular disease, both of which are considered foreign animal diseases of considerable importance to international trade. The only way to tell these diseases apart is with laboratory tests.

Any livestock with signs of a vesicular disease must be reported to the State Veterinarian’s Office in Colorado. To report a case in Colorado, call (303) 869-9130. Animals with clinical signs are then tested in order to rule out the other significant foreign animal diseases.

There is no vaccine for VSV, and the way it is transmitted is not completely understood. It appears to move in three ways:

  • via insect vectors (black flies, sand flies, biting midges)
  • mechanically on shared equipment, clothes, boots
  • contact of infected animals

Decrease the likelihood that livestock will get VSV by following the same commonsense biosecurity steps used to avoid many types of infectious diseases:

  • Strict fly control.
  • Avoid sharing equipment — feed tubs and water buckets, pitchforks, tack and halters, brushes and health care equipment — between herds or individuals.
  • Check your animals on a regular basis for signs of lesions. If any signs are seen, isolate the animal away from the other susceptible animals on the property. Do not take them to a community event where other animals may be exposed. Report any lesions or abnormalities to your veterinarian or state health official.
  • When returning home from an activity where your animals mixed with other animals, keep them away from the home herd for at least a week to be sure they are still healthy.
  • Clean equipment carefully before sharing with home herd.
woman in a blue v-neck t-shirt
Dr. Ragan Adams

Download the USDA/Animal and Plant Health Inspection Service’s fact sheet on VSV.

Ragan Adams, D.V.M., is coordinator of the Veterinary Extension Specialist Group at Colorado State University.