Since 2022, it has been verified that over 80 domestic cats, including those in Oregon, have contracted bird flu. These cats are mostly barn cats that resided on dairy farms, feral cats, and pets that spend time outside and most likely contracted the illness by hunting sick rodents or wild birds.
Recently, a small but increasing number of house cats have contracted H5N1, the strain of avian flu that is causing the current outbreak in the United States, after consuming raw food or unpasteurized milk. A few of those felines passed away.
The strain of avian flu that is now in circulation has not evolved to spread among humans effectively. Also, throughout the present H5N1 outbreak, there have been no documented instances of cat-to-human transmission.
However, there is always a chance that cats, who are arguably only semi-domesticated, could bring an illness home with them after their midnight hunt.
According to virologist Angela Rasmussen, who researches disease progression in emerging viruses at the University of Saskatchewan Vaccine and Infectious Disease Organization, companion animals—particularly cats—are a complete public health danger in terms of the possibility of zoonotic transmission to humans.
This is because we lay in bed with our cats and cuddle with them. Cats walk on kitchen counters and sip from our water cups when we’re not looking. Therefore, cat owners need to be mindful of the continued spread of avian flu. According to Rasmussen, lowering the risk to your cats also lowers the risk to you.
Taking safeguards is beneficial for both public health and pets, according to Rasmussen, but he does not believe pet owners need be concerned that their cats would infect them with bird flu.
According to Michael Q. Bailey, the president-elect of the American Veterinary Medical Association, a runny nose and discharge around the eyes are symptoms of avian flu in cats.
In addition, H5N1 causes neurological issues like convulsions and vertigo, which are signs of rabies. Any animal suspected of having rabies must be put down because the virus is nearly always lethal and can endanger human health. Bailey advises folks to make sure their pets’ vaccines are current.
Even if your cat spends time outside or consumes raw food, you shouldn’t assume that it’s bird flu, according to veterinarian Jane Sykes of the University of California-Davis School of Veterinary Medicine, who specializes in infectious disorders in cats and dogs. While H5N1 is still relatively uncommon in cats, upper-respiratory diseases are prevalent.
Sykes only feeds Freckles, her indoor cat, ordinary kibble. She told NPR and KFF Health News that since viruses are killed by heating when dry or canned pet food is made, she is not worried about Freckles contracting H5N1.
Human Risk Increases with Cat Cases
Because they believe it to be a more natural or nutrient-dense diet, some individuals give their pets raw meat or unpasteurized milk. This is discouraged on the website of the American Veterinary Medical Association because of foodborne infections like listeria and salmonella, as well as the now exceedingly dangerous H5N1.
Veterinarians are crucial in preventing zoonotic infections in humans by maintaining the health of pets. The danger of H5N1 spreading from a pet to a human is very low, but not nil, according to the American Veterinary Medical Association.
Similar cautions against feeding pets raw food have been issued by state and local public health organizations, such as those in Washington state and Los Angeles County.
The FDA said last month that it is now forcing cat and dog food producers to revise their safety procedures to defend against avian flu, in part due to concerns about human health.
This followed the Oregon Department of Agriculture’s discovery that a cat that was exclusively kept indoors had died after ingesting a frozen turkey product manufactured by the raw pet food company Northwest Naturals and had contracted H5N1. Tests revealed that the virus in the raw and frozen pet food and the afflicted cat shared a genetic match, according to the statement.
That batch of Northwest Naturals’ frozen turkey-based product was voluntarily recalled. The company expressed doubts regarding the accuracy of the Oregon Agriculture Department’s tests and stated that the recall involved a small product run, as reported by KFF Health News and NPR.
Five cats from two households tested positive for avian flu after consuming unpasteurized raw milk from the Raw Farm dairy in the Central Valley of California, according to the public health department of Los Angeles County.
After retail products tested positive for H5N1, Raw Farm voluntarily recalled its milk and cream; nonetheless, it denies any food safety concerns and refers to the problem as a political one.
Additionally, veterinarians caution pet owners against letting their cats spend unsupervised time outdoors since they run the danger of contracting H5N1 from associating with other animals that may be infected.
According to Bruce Kornreich, head of Cornell University’s Feline Health Center, this virus is quite frightening because it may infect a wide variety of host species.
In 2016, there was at least one case of a cat spreading avian flu to a human. A veterinarian in New York City contracted the illness after coming into close contact with infected cats, according to NPR. The veterinarian recovered rapidly after experiencing moderate symptoms.
In that instance, the bird flu strain was H7N2, not the current H5N1 variant that is circulating in the United States.
According to Sykes, H7N2 is a completely new kind of virus. However, she said that it demonstrates the potential for cat-to-human avian influenza transmission.
Although there isn’t much research on how bird flu might spread from pets like dogs or cats to people, Rasmussen acknowledged that it is a concern: The more infections you have in animals, the more likely it is that you will eventually run out of luck.
Agricultural workers who have come into close contact with sick animals or poultry make up the majority of H5N1 cases. One fatality has occurred in an immunocompromised individual who came into contact with birds out of at least 67 confirmed human cases of H5N1 in the United States.
Researchers studying zoonotic diseases generally wish to see more H5N1 surveillance in all kinds of companion animals. H5N1 is still a threat to public health even if the number of fatalities is still quite low.
Potential for Mutation
This H5N1 outbreak is concerning in part because avian flu viruses are subject to change. A few changes could make this strain more adept at transmitting from person to person. And the more people who catch H5N1, the more likely it would adapt to be more efficient, saidSuresh Kuchipudi, a virologist at the University of Pittsburgh School of Public Health, where he researches zoonotic diseases.Kuchipudi has researched feline H5N1.
Something known as reassortment is another issue. If an animal or person is infected with two viruses at once, the viruses can trade genetic material, creating something new. This is common in influenza, so virologists are on the lookout for a case in which the bird flu reassorts to make a virus that s far more contagious, and potentially more virulent.
Virologist Rasmussen is way more worried about this happening in pigs. Human respiratory physiology is more like that of swines than felines. So far, the current outbreak of H5N1 has not reached commercial hog operations. Rasmussen hopes it stays that way.
Kuchipudi said that reassortments are relatively rare events, but the outcome is completely unpredictable. Sometimes the results are benign, though it was likely a reassortment that involved an avian virus that led to the 1918 flu pandemic, which killed anestimated 50 million people. In the century since, virologists have established a global surveillance network to monitor influenza viruses. Scientists saycontinued investment in this network is keyto preparing for and hopefully preventing another pandemic.
Winter is reassortment season because of all the influenza viruses circulating, Rasmussen said. A reassortment in cats could technically be possible since these petsoccasionally get seasonal flu, but it s highly unlikely. Rather, Rasmussen said, it s more likely that a cat would pass H5N1 to a human who already has seasonal flu, and then a reassortment happens in the sick person. While the risk isn t zero, Rasmussen doubts this will happen. It would depend on how ill the human was, and how much virus they re exposed to from their cat.
Unless the cat is really shedding a ton of virus, and you re kind of making out with the cat, I think it would be hard, she said.
Rasmussen and Kuchipudi caution there isn t enough research to know for sure how much virus cats shed, or even how they shed the virus.
The Centers for Disease Control and Preventionwas poised to releasea new study about H5N1 in cats, but that was delayed when the Trump administration paused the Morbidity and Mortality Weekly Report. That investigation, revealed through emails obtained by KFF Health News in a public records request, foundthat house catslikely got bird flu from dairy workers.
Scientists and public health agencies should question previously held assumptions about bird flu, Kuchipudi urged. He noted that 20 years ago nobody would have predicted that bird flu would infect dairy cattle the way it is now.
Dogs Seem To Fare Better
TheFDA saysother domesticated animals, including dogs, can get bird flu infections. There are no confirmed cases of H5N1 among dogs in the U.S., though in other countries they have died from the virus.
There s some disagreement and an overall lack of research on whether cat biology makes them more susceptible to H5N1 than other mammals, including humans, pigs, or dogs.
But cat behaviors, such as their love of dairy and predation of wild birds, put them at higher risk, Kuchipudi said. Also, living in groups might play a role as there are more feral cat colonies in the U.S. than packs of stray dogs.
There s very little people can do about the H5N1 circulating in wild birds. As Rasmussen explained, It s flying around in the skies. It s migrating north and south with the seasons.
But she said there s a lot people can do to keep the virus out of their homes.
That includes limiting a pet s exposure to H5N1 by not feeding them raw food or unpasteurized milk, and trying to keep them from interacting with animals like rodents and wild birds that could be infected with the virus.
This article is from a partnership that includesNPRand KFF Health News.