Until 2000, virtually every state in the U.S. was identified as free from bovine tuberculosis, says Brian McCluskey, director of veterinary services for the Western Region of USDA's Animal and Plant Health Inspection Service (APHIS).
But eight states have since changed that. California and New Mexico are the latest states to see their TB ranking be downgraded. The disease has already been detected in Arizona, Colorado, Michigan, Minnesota, Oklahoma and Texas.
"It is a worrisome trend,” McCluskey says. While he points to imported cattle as a probable source, McCluskey is also concerned that new management trends might pose additional risks for the disease. For example, heifers may go to a heifer raiser that sits close to a feedlot that has taken in Mexican cattle.
"Producers need to take a hard look at their on-farm practices and bio-security,” McCluskey says. "Know the history of replacements. It's important that you don't buy in the disease.”