Bird flu has killed dozens of cats around the world. Is your cat at risk?

Cows and, of course, birds are the focus of attention in the avian flu outbreak – but they are not the only animals infected with the H5N1 virus. Cats are increasingly becoming the focus of this growing health crisis, which is particularly worrying because they drink milk on dairy farms and eat birds and mice, which have recently been reported as reservoirs for the virus.

When cats die from bird flu, it can be gruesome, suffering from fever, loss of appetite, and severe respiratory and neurological symptoms that are uncomfortable and painful.

As reported in the journal Emerging Infectious Diseases of the U.S. Centers for Disease Control and Prevention, more than half of the cats around the first Texas dairy farm to test positive for bird flu this spring died after drinking raw milk from infected cows.

“The cats were found dead with no visible signs of injury and were part of a population of (approximately) 24 domestic cats that had been fed milk from sick cows,” the scientists wrote. “Clinical illness in cows on this farm was first noted on March 16; the cats became ill on March 17, and several cats died in a cluster between March 19 and 20.”

The presence of H5N1 in birds has been known since 1996, but the current situation only began to worsen in 2021 and has killed hundreds of millions of birds worldwide in just a few years. Other mammals, including seals and bears, are also infected. However, this latest outbreak in the U.S. is the first time health officials have confirmed the virus has jumped from a cow to a human. Since the outbreak, there have been three reported cases of humans contracting bird flu this way — though experts say there are very likely more cases — and at least 90 dairy herds in 12 states have been affected.

Additionally, at least 9,398 wild birds have been confirmed to have avian influenza. Considering that cats are predators with a hunting instinct, especially sometimes against birds, are domestic cats that live outside at risk of contracting avian influenza? And should cat owners take precautions, such as keeping their outdoor cats indoors?

Dr. Rajendram Rajnarayanan of the New York Institute of Technology’s Jonesboro, Arkansas, campus told Salon that experts don’t really know the extent of the situation and its impact on pets like cats.

“I don’t see a big risk in terms of the spread of H5N1 among domestic cats. Yes, there are some domestic cats that have been reported,” Rajnarayanan said. “But I would look for good hygiene practices in general and then I would suggest looking for signs of disease.”

Another problem area to watch out for is feeding your cat raw meat. In the summer of 2023, an outbreak of bird flu in Poland raised alarm when more than 45 cats died in 13 geographic regions of the country. Tests found that 29 of them were infected with H5N1. Experts suspected that raw meat was linked to the outbreak. Cats kept indoors have also died from bird flu, according to a 2023 study of 40 shelter cats in South Korea, 38 of which died from duck meat cat food contaminated with bird flu.

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Daniel Goldhill, a virologist at the Royal Veterinary College, told Salon: “If you live on a farm and have cats that get raw milk from the cows, you should be extremely cautious about consuming raw milk.”

“One of the reasons veterinarians realized that bird flu had spread to cows, which they hadn’t expected, was because they were seeing cats and birds dying on various farms where cows were getting sick,” Goldhill said. “Most of the cats we’ve infected got it that way – they lived on farms.”

But that is not the only possibility, Goldhill stresses. There are reports of cases in which cats have become infected directly from wild birds.

“If a cat gets infected by a bird that has avian influenza, in some cases it can get avian influenza,” he said. “And if avian influenza successfully spreads in the cat, it can spread systemically in the cat, get into the cat’s brain, and then the cat can die.”

Goldhill stressed that the number of cats that have died this way is quite small. Asked whether cat owners should keep their outdoor cats indoors, he said you need to be aware of the possibility of bird flu – especially if you live on a farm. However, in his opinion, it is “more likely that a normal house cat will get hit by a car”. Of course, cats can also catch many other diseases if they have uncontrolled access to the outdoors, including rabies, ringworm, Salmonella and the feline immunodeficiency virus (FIV), which is essentially equivalent to the HIV virus in humans.

Experts have been warning for years that if bird flu spread to pigs, it would be time to press the panic button. Pigs are genetically closer to humans and act as a major reservoir for viruses that mutate into something that could cause a widespread pandemic in humans. Is the fact that cats are being infected also a cause for concern?

“In cats, we don’t really see that sustained transmission, we don’t see that sustained transmission in cats,” Goldhill said. “There’s much less opportunity for the virus to spread between cats and develop traits that could transmit it to humans.”

Even more concerning are minks and ferrets, he said. “They have receptors that are much more similar to human receptors in their respiratory tract,” he said. In fact, a study released Friday by the Centers for Disease Control and Prevention found that ferrets are particularly susceptible to the H5N1 strain that infected a human in Texas. The virus was 100 percent fatal in all six infected ferrets.

“This is very worrying,” said Rick A. Bright, former chairman of the Pandemic Prevention Institute and influenza virus expertsaid on X (formerly Twitter). “Efforts to change the narrative in any way to dilute these important data are reckless. Ferrets are the animal model commonly used for human infection. The fact that they became so severely ill, the virus infected most of their internal organs and brain, and they died, sends a strong signal that any effort to stop the spread of this virus should be seriously considered.”

In other words, cats may be the least of our worries.