USDA-APHIS downgrades California’s bovine TB status

USDA’s Animal and Plant Health Inspection Service (APHIS) is reclassifying California‘s status to “modified accredited advanced” for bovine tuberculosis.

This week’s downgrade is the result of cows in three Fresno County dairy herds testing positive for bovine TB in the last year. Before the reclassification, California had held an “Accredited Free” status.

USDA and California Department of Food and Agriculture (CDFA) personnel continue efforts to investigate those cases. Veterinarians and animal health professionals from across the state and nation are helping with the effort.

Because of the APHIS action, breeding cattle or bison leaving California will require a negative tuberculin test before they move, CDFA said. Spayed heifers and steers, cattle from TB-accredited free herds, cattle moving to packing plants, cattle or bison less than 6 months of age, and intact heifers moving directly to a feedlot can move to most states without testing.

Since this bovine tuberculosis investigation began in December 2007, more than 145 herds and over 180,000 cattle have been tested, according to CDFA. Seven infected cattle have been identified. Although the source of the infection has not been identified, the bacteria strain-type in one herd differs from that in the other two herds, and both are typical of those infecting dairy cattle in the Southwest U.S. and Mexican origin cattle.

All cattle from two of the affected herds have been removed and the third herd is under movement controls and a testing program to remove infected cattle and prevent any spread of disease.

California will be eligible to reapply for Free-status two years after the quarantine is released on the last affected herd.

APHIS also downgraded New Mexico‘s bovine TB status last week to Modified Accredited Advanced from its previous “split-state” status.

Bovine tuberculosis does not threaten the quality and safety of milk and meat products produced in California, CDFA said.

Bovine tuberculosis is caused by Mycobacterium bovis, an organism very similar to the bacteria causing human tuberculosis. It can affect cattle, bison, deer, elk and other warm-blooded species, and can be fatal.

Catherine Merlo is Western editor for Dairy Today. You can reach her at cmerlo@farmjournal.com.