On April 24, the U.S. Department of Agriculture's (USDA) Animal and Plant Health Inspection Service (APHIS) confirmed the nation's 4th case of bovine spongiform encephalopathy (BSE) in an animal that was sampled for the disease at a rendering facility in central California. This animal was never presented for slaughter for human consumption, so at no time presented a risk to the food supply or to human health in the United States.
After USDA's National Veterinary Services Laboratories (NVSL) completed testing of the samples from the index animal, the samples were sent to the World Organization for Animal Health (OIE) reference laboratories in Canada and England. Both laboratories have confirmed that the index cow was positive for atypical (L-type) BSE.
Both dairies that were previously held under quarantine during the investigation have been released from those quarantines, after inventories were completed and records were reviewed. In addition, investigation of the feed records at the index dairy premises found no anomalies, and audits of all the feed suppliers to the index premises have shown them to be in compliance with the regulations.
APHIS previously announced that it has identified two progeny of the positive cow. One progeny born to the positive cow in the last two years was stillborn; the second animal was appraised, humanely euthanized and sampled for BSE at the NVSL in Ames, Iowa. Test results for that animal were negative for BSE. Of several hundred potential birth cohort cattle, the focus of the tracing is on a small number (10-12) of cattle which may still be alive and have records that might allow them to be located. The remaining potential cohorts are no longer alive or have otherwise been ruled out.