More cases of vesicular stomatitis in horses have been reported to authorities in Colorado and Texas, but the tide appears to be turning in the outbreak first reported in May.
The latest update from the Animal and Plant Health Inspection Service (APHIS), a division of the US Department of Agriculture, showed that 256 horses and 15 cattle were considered to be currently positive for the disease as at 5pm on Tuesday.
In the report issued a week before, 303 horses and nine cattle were considered positive.
Since that report, dated September 10, a total of 23 new positive premises have been confirmed in the two states. Colorado reported 16 new equine premises and four new premises involving cattle, and Texas reported three new equine premises.
All cases since the outbreak began have been confirmed as the New Jersey serotype.
Authorities provided the following breakdown of the latest cases by county:
- Adams County, Colorado – 1 horse on 1 premises.
- Jefferson County, Colorado– 5 horses on 3 premises.
- Larimer County, Colorado -12 horses and 5 cattle on 10 premises.
- Pueblo County, Colorado – 5 horses on 3 premises.
- Weld County, Colorado – 1 horse and 5 cattle on 3 premises.
- Bastrop County, Texas – 4 horses on 2 premises.
- Lee County, Texas (newly affected county) – 2 horses on 1 premises. APHIS said the horses on this property in Lee County were confirmed to have been infected in Bastrop County, but were illegally moved to Lee County and remained there under quarantine.
To date, a total of 358 positive premises have been identified in the two states – 297 in Colorado and 61 in Texas.
There have been 13 counties affected in Colorado (Adams, Arapahoe, Boulder, Broomfield, Douglas, El Paso, Fremont, Jefferson, Larimer, Logan, Morgan, Pueblo, and Weld); and 13 affected in Texas (Bastrop, Falls, Guadalupe, Hidalgo, Jim Wells, Kinney, Lee, McLennan, Nueces, San Patricio, Travis, Val Verde, and Williamson).
Of the 358 total premises, 344 have been positive equine premises, 12 have been positive cattle premises, and two have had both cattle and horses positive.
Positive premises are eligible for quarantine release 21 days after lesions have healed in all affected animals. To date, 46 properties in Texas and 129 in Colorado have been released from quarantine.
There are an additional 14 properties in Texas and 96 in Colorado on the 21-day countdown to quarantine release.
To date, 502 horses and 25 cattle have tested positive since the outbreak began.
Vesicular stomatitis can cause blisters and sores in the mouth and on the tongue, muzzle, teats or hooves of horses, cattle, swine, sheep, goats, llamas and a number of other animals.
Lesions usually heal in two or three weeks.
Because of the contagious nature of the disease, which has symptoms similar to foot and mouth disease, animal health officials urge livestock owners and caretakers to report these symptoms to their veterinarian immediately.
Most animals recover well with supportive care by a veterinarian, but some lesions can be painful.
It is thought that insects are an important vector in the transmission of the disease.
Several states have imposed more restrictions on the movement of stock originating from Texas and Colorado as a result of the outbreak.