Six US states have reported confirmed cases of vesicular stomatitis virus, with three equine premises in Utah the latest affected by the reportable viral disease that affects mostly cattle, horses, and swine.
Cases in Colorado, Nebraska, New Mexico, Texas, and Wyoming had earlier been confirmed by the United States Department of Agriculture (USDA) Animal and Plant Health Inspection Service (APHIS). An infected premises in Oklahoma had been released from quarantine earlier in the month.
In Utah, the cases are on a property in Emery County and two in Uintah County. The latest were notified in the USDA’s August 19 situation report, which noted the addition of 22 new affected premises since August 15.
Symptoms of vesicular stomatitis can resemble foot-and-mouth disease.
The first sign is often excessive salivation, and blister-like lesions in the mouth. The blisters swell and break, leaving raw tissue that is so painful that infected animals show signs of lameness and generally refuse to eat or drink. Severe weight loss may follow. Lesions usually heal in two or three weeks.
Outbreaks usually occur during the warmer months, often along waterways, and this most recent outbreak began on June 21, 2019 in Kinney County, Texas.
Vesicular stomatitis is an endemic disease in the warmer regions of North, Central, and South America, and outbreaks of the disease in other temperate geographic parts of the hemisphere occur sporadically. The most recent outbreak in the US occurred in 2015.
Premises that have laboratory diagnostic confirmation of vesicular stomatitis virus (VSV) are categorised as confirmed positive premises. Once a county is confirmed as VSV-positive, new equine premises presenting with clinical signs of VSV in that county are not required to be tested for confirmation of the disease, but the premises will be quarantined and classified as a suspect premises.
Confirmed positive and suspect premises are quarantined for at least 14 days from the onset of lesions in the last affected animal on the premises.