The Los Angeles County Department of Public Health said Thursday that it is investigating two possible cases of H5 bird flu in cats that consumed recalled raw milk from Raw Farm LLC.
The animals have died.
The two cats, indoor pets, reportedly consumed raw milk that was linked to the statewide recall of raw milk and cream products. After lapping up the product, the animals developed symptoms that included a lack of appetite, fever and signs of neurological problems.
Both animals died after symptoms severely worsened. And both animals tested positive for Influenza A.
Influenza A viruses include most human seasonal flu viruses as well bird flu variants, including H5N1.
County health authorities are considering the animals "presumptive" H5N1 bird flu cases. They have sought confirmatory testing.
Health officials said in a statement that people who had direct contact with the cats are now being monitored for symptoms and have been offered Tamiflu or other antiviral medications.
There have been no associated human infections with these cats.
Read more: Warning issued for contaminated raw milk sold in L.A. County stores
"The risk of H5 bird flu remains low in Los Angeles County, but this suspected case of the virus in a pet cat that consumed raw milk is a reminder that consuming raw dairy products can lead to severe illness in cats," said Barbara Ferrer, the director of the Los Angeles County Department of Public Health, in a statement.
She said the health department is encouraging residents and their pets to "avoid raw dairy and undercooked meat products, limit contact with sick or dead animals, report sick or dead birds and keep pets or poultry away from wild animals and birds."
It is unclear how many cats have died since H5N1 began circulating in dairy cows earlier this year. They are extremely susceptible to the virus, however, and dead barn cats are considered an early biological warning that a dairy has been affected by the virus.
At one Texas dairy farm, half of a cluster of 24 barn cats died after drinking infected raw milk.
Last year, the World Health Organization reported sporadic deaths of cats throughout areas known to be infected with H5N1 bird flu, including at one location in Poland, where a cluster of 46 died; 29 cats were found to be positive for the bird flu virus.
Larger cats, including captive lions, tigers and panthers, have also died as a result of eating meat contaminated with bird flu.
So, too, have wild California bobcats and mountain lions.
Symptoms of H5N1 infection in cats include labored breathing, bloody diarrhea and neurological abnormalities -- loss of motor control, seizures, depressed mental state, stiff body movements, blindness, circling, copious eye and nose discharge and coma -- with rapid deterioration and death in some cases.
Read more: Bird flu virus detected in California raw milk
Outdoor cats can also be exposed to bird flu by consuming infected birds or other animals and by being in environments contaminated with the virus, or by consuming unpasteurized milk from infected cows.
The statement noted that cats have transmitted other influenza strains to humans in the past, "but there have been no known cases to date of H5 bird flu transmitted from cats to humans as part of this nationwide H5 bird flu outbreak."
Last month's raw milk recall applied only to raw whole milk and cream products -- not to cheese, kefir, or pet food products made with raw milk, including "raw milk pet food topper" and "pet food kefir."
Health officials are urging people to avoid these products, as well.