Cattle TB confirmed at west Texas dairy

Austin, Texas

-- Cattle tuberculosis was confirmed in a west Texas dairy that was placed under quarantine when some animals in the herd responded to a TB test conducted prior to a sale.

The cattle TB diagnosis was confirmed at the National Veterinary Services Laboratory at Ames, Iowa, where M. bovis, the causative bacteria, were cultured from tissues collected during necropsies of the test-positive cattle.

The dairy remains under the quarantine that was imposed in April until final disposition of the herd is determined, which could be either slaughtering of the herd or repeated testing and removal of infected cattle until the herd is declared free of infection, according to Dr. Bob Hillman, Texas state veterinarian and head of the Texas Animal Health Commission (TAHC).

Tests are being conducted to find the origin and evaluate the risk of potential spread of the disease, Hillman says. He advised ranchers and veterinarians to call the state of destination before shipping bison, beef or dairy cattle out of Texas.

The state's TB-free status could be in jeopardy, Hillman says, if the infected dairy can't be depopulated or if a second infected herd is found within 48 months. When that status is lost, cattle and bison moved out of state need a negative TB test within 60 days prior to shipment. The USDA declared all Texas counties free of cattle TB in September 2006.

California and Minnesota currently are the only states not cattle TB-free; Michigan and New Mexico have some zones that are not TB-free.