Federal officials who have spent the past year dealing with a wave of bird flu infections in cows and humans are now dealing with a series of new cases in cats, some of which have died after eating contaminated, undercooked pet food.
Since early December, more than 22 cases have been confirmed in domestic cats in the United States. Officials have linked some of the cases to virus-laden raw milk, which is known to pose a serious risk to cats. But other cats became ill after eating commercially available raw pet food – the first known cases in the country linked to pet food.
The cases have already prompted one pet food manufacturer to recall some of its products. And last week, federal officials announced new pet food safety rules and poultry surveillance efforts.
Avian influenza “is an emerging food animal pathogen,” said Dr. Steve Grube, chief medical officer at the US Food and Drug Administration, in a briefing last week.
But experts and officials said there was no need for pet owners to panic. There is no evidence that infected cats have transmitted the virus to humans, and outbreaks have been linked specifically to unpasteurized milk and uncooked meat or poultry products.
Most commercial pet foods are cooked or heat-processed. “The heat of processing should be enough to inactivate the virus,” said Phyllis Entis, a food safety microbiologist who worked for Canada’s food safety agency.
However, the cat cases highlight the danger of raw food products and raise questions about safety and surveillance gaps in parts of the food supply chain.
“We really don’t have a sense of how widespread this virus is, and we’ve already seen quite a few cases sneaking out of pet food,” said Kristen Coleman, an infectious disease researcher at the University of Maryland. study of bird flu in cats. “It’s a really big vulnerability.”
Although dogs appear to be less susceptible to the virus than cats and generally show milder symptoms, contaminated food poses risks to canines as well.
Here’s what you need to know.
How do cats get infected?
Experts have long known that cats are susceptible to the virus, which is called H5N1 and is often fatal in felines. There have been sporadic deaths of cats preying on wild birds, and there has been an increase in cat cases since bird flu began circulating on dairy farms about a year ago. Raw milk from infected cows often contains very high levels of the virus. Farm cats that died after giving raw milk often served as an early sign of an epidemic.
(Pasteurization, a process in which milk is rapidly heated and then cooled, inactivates the virus and makes the milk safe to drink, according to the FDA)
Many of the recent infections have occurred in indoor cats that have had no known contact with wild birds or dairy farms.
In December, Oregon officials announced that a cat had contracted bird flu and died after eating raw, frozen pet food from Northwest Naturals. Samples of the food — the company’s Feline Turkey recipe — tested positive for H5N1, and the virus was a genetic match to the one found in the cat, officials said.
In an emailed statement, Northwest Naturals said the company had “deep concern about the accuracy of testing an open bag of pet food, which may contribute to cross-contamination and the introduction of external contaminants that could lead to false positive or inaccurate test results.”
However, the company decided to issue a voluntary recall.
California has also reported bird flu infections in cats fed raw milk or pet food. In a Los Angeles household, five cats became ill – and two died – after eating two types of raw pet food. Samples from one of the two brands, Monarch Raw Pet Food, tested positive for the virus, officials said.
“Monarch is complying with the notification from the local authorities. However, they are not requesting a recall and, to our knowledge, there have been no other cases involving Monarch,” Stephanie Greene, a company spokeswoman, said in an email.
How does the virus get into pet food?
It is not entirely clear and there may be different sources for different cases.
But in an email Wednesday, an FDA spokesman said some virus samples from infected cats were closely related, genetically, to samples from turkey farms in Minnesota.
When avian influenza is detected in a farmed turkey or chicken, federal regulations require that all birds in that flock be killed. Those birds “are not allowed in any food product,” Dr. Eric Dible, an official at the U.S. Department of Agriculture, said at the briefing last week.
Turkeys and chickens usually become very ill and die soon after infection. But if a bird picked up the virus just before it was slaughtered or somehow had a very mild infection, it could potentially slip into the food supply undetected, experts said.
The FDA, which regulates commercial pet foods, requires pet food manufacturers to develop written safety plans outlining the steps they take to ensure their products are safe for consumption.
The agency “has zero tolerance for pathogens like salmonella or listeria or E. coli or any other potential pathogen in ready-to-eat pet food, and that includes raw pet food,” Ms. Entis, who is the author of Toxic: From Factory to Food Bowl, pet food is a risky business.
(The FDA does not have an official definition of raw pet food, but generally, products marketed as “raw” have not undergone any heat treatment, such as cooking or pasteurization.)
But in practice, said Mr. Unfortunately, the agency doesn’t have many resources to regulate and oversee pet food. “So there’s a lot that doesn’t get caught or only gets caught when there are reports of illness,” he said.
Northwest Naturals said the pet food was processed in a facility that had a USDA inspector on site and also produced food for human consumption. “We remain completely confident in our strict quality control and its ability to ensure that our customers’ pets are served safe and nutritious food,” the company said.
What are the authorities doing about it?
Last Friday, the FDA announced new rules requiring companies that make pet foods containing certain uncooked or unpasteurized ingredients to update their food safety plans to account for the potential risks of bird flu.
Whether this will lead to meaningful security reforms remains to be seen, said Ms. Entis. Some companies may decide to implement new precautions, such as buying ingredients only from suppliers who regularly test their animals for the virus. But others could say they have reviewed existing security plans and decided no new safeguards are needed, Ms. Entis.
Northwest Naturals said it is working to “review and strengthen our already rigorous food safety plan.”
The USDA also announced new avian influenza surveillance guidelines for large, commercial turkey farms in Minnesota and South Dakota. The guidelines, which could be expanded to other states in the future, require turkeys to be isolated, monitored and tested for the virus 72 hours before they are sent for slaughter.
What can pet owners do?
The easiest way to protect your pets is to avoid feeding them raw milk, meat or poultry, experts agreed. These products, which can harbor a range of foodborne pathogens, have always posed health risks, and bird flu is increasing them. “It’s just not safe right now,” Dr. Coleman said.
Owners whose pets do well on a particular raw pet food—and are unwilling or unable to suddenly switch to a new product—can greatly reduce the risks by cooking the food before serving.
Pet owners should also use this as an opportunity to become more familiar with what’s in the food they serve their pets and how it’s processed, Dr. Coleman said. People with questions or concerns can contact pet food companies directly to ask where they source their ingredients and what food safety measures are in place. “And if they can’t give you an answer to these very simple questions, then there’s your answer — stop buying their product,” Dr. Coleman said.
People should also try to limit their pets’ contact with birds — and wildlife in general — and report sick and dead birds to local officials.
