USDA moved swiftly when news arrived of the discovery of a California cow infected with bovine spongiform encephalopathy. The animal was confirmed on April 24 as the fourth infected animal discovered in the United States. And it was found at a rendering facility in central California, where it was never presented for slaughter for human consumption and never was at risk of entering the food chain.
USDA's Animal Plant Health Inspection Service issued an update this week announcing that investigation is continuing on the case noting that all tests have shown that the cow was positive for atypical - or L-type - BSE.
Both dairies that were previously held under quarantine during the investigation have been releasted from those quarantines after inventories were completed and records were reviewed. And APHIS reports that investigation of the feed records at the index dairy premises has found no anomalies and audits of all the feed supplies to the premises have shown them to be in compliance with the regulations.
The agency announced earlier that it had identified two progeny of the positive cow. One was born to the positive cow in the last two years and was stillborn; the second animal was appraised, humanely euthanized, and sampled for BSE at the National Veterinary Services Laboratories in Ames, Iowa. Test results on that animal came back negative.
Of several hundred potential birth cohort cattle, the focus of the tracing is on a small number (10 to 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 by investigators.
As the investigation heads toward completion, APHIS reports that local officials from the California Department of Food and Agriculture, and APHIS Veterinary Services are now in charge of the incident command.