by Victoria G. Myers Progressive Farmer Senior Editor
BIRMINGHAM, Ala. (DTN) — Wyoming State Veterinarian Jim Logan is looking forward to some cold weather. Freezing temperatures should mark the end of this year's outbreak of vesicular stomatitis virus
It's been an unusually heavy year for the virus, which is primarily spread by flies and midges, and is identified only through the testing of samples taken from an affected animal. Those samples can include blood, tissue and/or swabs of lesions. Federal and state requirements classify VSV as a reportable animal disease.
“The first sign you'll usually see in cattle and horses, which are the two primary species we see affected by it, is they go off their feed,” said Logan. “Then they start to slobber because of sores in their mouth. The last couple of years, though, this virus has not always shown as lesions in the mouth. It may be in the ears, on udders, on genitals and sometimes on the outside of the muzzle. A lot of cases this year have had lesions on the band of soft tissue above the hoof.”
VSV does not generally cause death in animals. What makes VSV such a high-priority disease is the similarity it has, in terms of symptoms, with Foot and Mouth Disease (FMD). For this reason, VSV test samples are sent to the Plum Island Animal Disease Center in New York. This facility is the only laboratory in the nation that can work on live FMD virus.
In addition to cattle and horses, USDA's Animal and Plant Health Inspection Service reports the disease can affect swine, sheep, goats, llamas and alpacas.
Wyoming is one of five states that still had premises under quarantine at the time this story was written. This year marked a VSV outbreak that resulted in 615 VSV-affected premises across eight states: Arizona, Colorado, Nebraska, New Mexico, South Dakota, Texas, Utah and Wyoming. The most recent data still had Colorado, Nebraska, New Mexico, Utah and Wyoming with a combined total of 114 quarantined premises.
In one week's time (Oct. 7 to Oct. 14) the number of VSV confirmed or suspected cases nationwide jumped by 60. The first confirmed case was found April 29 in Grant County, New Mexico, in a horse.
Once an animal has been identified as having VSV, the premises is put under quarantine. APHIS factsheet “Vesicular Stomatitis” states: “Premises containing affected animals are quarantined until 21 days after the lesions in the last affected animals have healed.”
It is recommended animals with lesions be separated from healthy animals. There is some research that suggests the virus can be spread more easily in a pasture environment.
VSV can also infect people, so it is recommended that handlers of affected animals wear protective clothing and gloves. APHIS reports that in people VSV causes an acute influenza-like illness with fever, aches, headache and weakness.
There is no vaccine for VSV and no treatment. The lesions are painful and take time to heal. Logan said producers can reduce the risk for VSV by keeping their operations cleaned up and free of stagnant water and overgrowth, which tend to draw insects that spread VSV. Insecticide sprays can also be effective in some cases.
After the quarantine period, Logan stresses meat from VSV animals is safe for consumers. “Proper heating and handling will do away with the virus,” he stressed. “VSV is not a food safety issue.”
All confirmed cases of VSV are reported to interstate and international trading partners. This can result in restrictions, additional inspections or testing. Prior to shipping livestock during an outbreak, it is recommended producers check with their state of destination to be sure all entry requirements are met.
To see the most current information on VSV from APHIS, search for “vesicular stomatitis” on their website at: www.aphis.usda.gov/wps/portal/aphis/ourfocus/animalhealth
© Copyright 2015 DTN/The Progressive Farmer. All rights reserved.