A wave of cat deaths from bird flu leads to new rules on pet food production

As experts continue to monitor and study the country’s environment and food supplies to combat the H5N1 bird flu, a series of dead cats has many officials concerned.

From pet cats in Los Angeles County and Oregon to captive feral cats in Washington and Colorado, dozens of felines have died from consuming raw pet food and milk infected with H5N1.

Although products carrying the virus have been widely marketed to animals — with the exception of raw milk — experts say the presence of the virus in commercial meat and dairy products highlights the vulnerability of the U.S. food chain to this virus.

“With multiple diagnosed cases of H5N1 mortalities, can we in good conscience not warn the general public that raw meat… has been linked to multiple big cat mortalities,” said John Korslund , a retired veterinary epidemiologist with the U.S. Department of Agriculture, in an email.

The deaths prompted policy changes announced Friday by the USDA and the Food and Drug Administration, which focus on pre-slaughter rules for some poultry farms in Minnesota and South Dakota, as well as changes in food safety risk assessments for raw pet food producers.

And they highlight the murky and largely unregulated industry of raw pet food manufacturing.

Although the FDA offers best practice guidance to raw pet food producers, there are few, if any, rules regarding how raw meat is obtained for pet food; Industrious entrepreneurs may source meat and protein from wild game, herds and backyard farms not inspected by the USDA, as well as meat not considered fit or palatable for human consumption – provided that it “is safe to eat, produced under sanitary conditions, contains no harmful substances and is honestly labeled”, in accordance with the Federal Food, Drug and Cosmetic Act, the law that governs animal foods of company.

The agency will also investigate businesses if animals became ill after eating pet food. And birds affected by the virus are not allowed into the food supply, per USDA regulations.

“Clearly, much of the protein produced outside of (USDA) Food Safety and Inspection Services-inspected facilities is never intended for human consumption,” said Eric Deeble, deputy USDA Assistant Secretary for Marketing and Regulatory Programs, during a press conference. press conference Thursday. But birds infected with H5N1 “are not allowed in any food product.” They are most often composted on site as part of efforts to mitigate the spread of the virus.

In Los Angeles County alone, nine cats became ill or died after eating raw milk, raw pet food or both containing the H5N1 bird flu virus. On Monday, county public health officials said five indoor cats in one home became ill after eating Monarch (based in San Jacinto, Calif.) raw pet food; two died.

In December, 20 captive feral cats – including four cougars and a half Bengal tiger/half Siberian – died after eating raw pet food contaminated with H5N1 at an animal sanctuary in Shelton, Washington. Five other animals at a private animal sanctuary in Shelton, Washington. The Coloradoan – two tigers, a lion, a mountain lion and a fox – also died from eating this food. So did two house cats – one in Oregon, another in Colorado.

In all but nine of the Washington cats, the genetic sequencing of their H5N1 virus matched samples taken from frozen turkey packaged in May and June by the Oregon-based company Northwest Naturals with pet food, according to the data published by the USDA Animal and Plant Health Inspection. Service, GISAID (a public genetic database focused on influenza viruses), the National Institutes of Health’s GenBank, and the World Organization for Animal Health, an international organization dedicated to disease investigation and surveillance animals. The meat was raw when frozen.

According to evolutionary molecular biologist Henry Niman, in each case there is a signature mutation on a segment of the virus – a switch at position 52 on the NP protein – in both food samples and dead animals, providing a unmistakable link between them.

Only the Oregon domestic cat has been positively linked by state and federal agencies to the Northwest Naturals brand. Although the other cats were killed by a virus genetically identical to that found in the Oregon cat and in the Northwest Naturals food samples, it is possible that these animals were fed food from the same meat or from the same epidemic, but under a different brand.

Questions sent to Northwest Naturals went unanswered.

Northwest Naturals voluntarily recalled the suspect lot: two-pound plastic bags with “Best If Used By” dates of 05/21/26 B10 and 06/23/2026 B1. And on its website, the company suggests that the sample was contaminated after packaging and production.

“Testing an open bag of pet food leaves open the possibility that the virus could have entered the bag after it was opened,” the company wrote on an FAQ page about the recall.

The observed change in genetic sequences, Niman said, “is extremely rare. And aside from the Northwest Naturals samples and the animals that ate them, “the only three other animals to show this change in this latest H5N1 outbreak were three commercial turkeys from Minnesota that were put down in June following an infection – the same month pet food was processed and packaged.

Niman said there is no way to show from genomic sequencing that it was turkeys from that Minnesota farm that were introduced into the pet food, but the virus was likely moving into the region at that time. And somehow, he says, the infected birds must have entered the slaughterhouse without anyone noticing — a phenomenon that most researchers say should be extremely rare. Commercial poultry typically show symptoms within a few hours of H5N1 infection and die almost immediately.

Maurice Pitesky, an associate professor who studies the epidemiology of poultry health and food safety at UC Davis, agrees. “I’m not sure, but maybe the birds were infected just before slaughter?” he said in an email, adding that “he didn’t know there are any companies that sell raw poultry for consumption by pets.

But if infected turkeys make it to the slaughterhouse unidentified, that suggests there could be more infected meat, said Korslund, a former USDA veterinary epidemiologist.

And that’s what worries researchers and health officials at the USDA and FDA.

On Friday, the USDA announced the launch of a new policy for turkey farms in Minnesota and South Dakota with more than 500 birds: birds will be required to undergo pre-slaughter inspection and isolation 72 hours before slaughter. ‘slaughter. The agency noted the link between infected turkeys and the Oregon domestic cat as the reason for the new program.

At the same time, the FDA cited “cases of H5N1 in domestic and feral cats in California, Colorado, Oregon and Washington state, associated with consumption of contaminated food products” as reason for calling the raw pet food processors to reanalyze their food safety systems. and integrate H5N1 into their analyses.

“The FDA has determined that it is necessary for cat and dog food manufacturers…that use raw or unpasteurized materials derived from poultry or cattle…in cat or dog foods, to reanalyze their food safety plans to include H5N1 as a known or reasonably foreseeable new hazard.

It is likely that it will continue to attack cats to signal the presence of the virus in food and the environment.

Scientists say cats are extremely susceptible to infection with the H5N1 virus. Since the outbreak was first reported in a Texas dairy herd last March, dead barn cats have served as sentinel warnings to veterinarians and investigators of the virus’s presence on a farm.

In cats, the virus can affect the brain and nervous system. Many suffer from blindness, seizures and abnormal behavior. Autopsies often show large amounts of virus in their brains.

And if the death of these cats is alarming in terms of conservation and protection of animals whose habitats are destroyed and whose populations are increasingly marginalized, it is the death of captive cats, scientists say, which should worry public health authorities. This is a sign that the virus is entering the commercial meat and milk supply – a worrying development, but not surprising given the presence of the virus in dairy cattle and commercial poultry farms.

Health officials say the best way to avoid infection is to cook meat thoroughly and eat only pasteurized dairy products – and to stop feeding raw meat and dairy products – commercial or not – to pets.