Federal health officials are warning that certain lots of raw cat food may be contaminated with H5N1 bird flu after a pet cat in San Francisco that ate the food became infected with the virus and had to be euthanized.

The U.S. Food and Drug Administration said Wednesday that two lots of RAWR Raw Cat Food Chicken Eats tested positive for the virus. Analysis by San Francisco health department officials showed that the same strain of the H5N1 virus was present in the pet food and in the cat that died.

The incident is the first reported case of an H5N1 infection from raw food in pet cats since March. Dozens of domestic cats, including nearly 70 this year, have been infected with H5N1, according to the U.S. Agriculture Department. Many of the animals became infected after consuming raw milk or raw pet food contaminated with the virus.

The affected lots of RAWR food include CCS 25 077, with a sell-by date of Sept. 18, 2026, and CCS 250 093, with a sell-by date of Oct. 3, 2026. RAWR raw pet food is sold frozen and must be thawed before use. No recall was posted for the products and representatives for the Grass Valley, California, company did not immediately respond to questions about the contamination.

RAWR Raw Cat Food Chicken Eats are sold in frozen 2.5-pound resealable bags containing 40 1-ounce sliders of food. The product is sold in stores nationwide and online.

The U.S. Agriculture Department's National Veterinary Services Laboratories confirmed the virus in samples from the food and the cat. Genetic sequencing showed that they contained a virus lineage that was detected in November and December and is no longer circulating. The virus is the same type that has been circulating widely in birds and in U.S. dairy cattle, including those in California.

H5N1 infections can cause illness and death in birds, poultry and mammals such as cats. The virus has not been detected in dogs in the U.S., but there have been fatal cases in other countries. Animals that are very young, very old or have weakened immune systems are at risk of becoming seriously ill from an infection.

No human infections from H5N1 bird flu have been identified in people who handled raw pet food, but humans can become infected and sick if active virus gets into their eyes, nose or mouth.

-- The Associated Press Health and Science Department receives support from the Howard Hughes Medical Institute's Department of Science Education and the Robert Wood Johnson Foundation. The AP is solely responsible for all content.