Consuming meat from cattle with eye cancer involves no known disease risk to humans and the beef sometimes passes federal inspection and makes it to the public's dinner plate, say food safety experts.
The issue surfaced last week with allegations that the embattled Rancho Feeding Corp. of Petaluma may have circumvented federal regulations by slaughtering cancer-stricken cows.
Confirmation came in a U.S. Department of Agriculture Food Safety and Inspection Service letter that said an investigation showed Rancho sold cattle "likely affected with epithelioma of the eye."
The Jan. 14 letter, first reported Wednesday by the Los Angeles Times, said that regulators found two cattle heads that had made it to market intact and with "skin still attached, and had no incisions for the four pair of lymph nodes on the head, which normally are incised for inspection."
The cattle heads did not have the USDA's mark of condemnation, which would prevent them from being sold, the letter said.
Rancho's plant — shuttered on Feb. 9 — is under investigation by the USDA and the U.S. Attorney's Office and the 8.7 million pounds of beef and veal produced there last year have been recalled.
No illnesses related to the meat have been reported, and much of it presumably has been consumed.
A call to Rancho co-owner Robert Singleton on Thursday was not returned.
The business is known to have purchased retired dairy cattle for slaughter and sale, and handled slaughtering for custom beef ranchers who market their own meat.
Post-mortem inspection of slaughtered cattle starts with the head, and officials have the option of rejecting either the head or the entire carcass of an animal with eye cancer, a former USDA veterinarian told The Press Democrat.