The first major global review of bird flu in cats reveals an emerging threat of a potential human pandemic.
Spring is here, birds are on the move, and a new threat is spreading alongside them: bird flu (H5N1). This virus is changing fast and could be on the path to becoming a human pandemic. Scientists from the University of Maryland School of Public Health have recently published a major study in Open Forum Infectious Diseases highlighting a surprising new concern. They found that cats are catching bird flu more often, and they’re calling for urgent monitoring to help stop the virus before it can spread between people.
“The virus has evolved, and the way that it jumps between species – from birds to cats, and now between cows and cats, cats and humans – is very concerning. As summer approaches, we are anticipating cases on farms and in the wild to rise again,” says lead and senior author Dr. Kristen Coleman, assistant professor in UMD School of Public Health’s Department of Global, Environmental and Occupational Health and affiliate professor in UMD’s Department of Veterinary Medicine.
“Bird flu is very deadly to cats, and we urgently need to figure out how widespread the virus is in cat populations to better assess spillover risk to humans,” she said. “We want to help protect both people and pets.”
Looking at data from 2004 to 2024, researchers uncovered 607 cases of bird flu in cats around the world, including 302 deaths. These cases spanned 18 countries and involved 12 different types of cats, from household pets to big cats like tigers. Despite the growing threat, cats are not routinely tested for bird flu. In most cases, testing only happens after the animal has died. Because of this limited surveillance, the real number of infections is likely much higher, according to lead researcher Dr. Kristen Coleman.
Increasing Transmission Pathways
Yet the ways cats are getting bird flu are multiplying. The study shows cats contract bird flu directly by eating infected birds or contaminated raw chicken feed, and indirectly through other mammals – for example, farm cats fed raw milk from infected cows, pet cats to other pet cats, tigers to other tigers.
Infected cats often suffer from acute encephalitis (brain swelling) and other severe symptoms, which are mistaken for rabies, according to the study. The most deadly strain of bird flu is highly infectious and makes up the majority of cases in domestic cats, with a current 90% case fatality rate.
In humans, bird flu is slightly less deadly, but still has killed around half of the 950 people infected with it globally. Between April 28, 2022 (when cumulative data on humans in the U.S. started being collected) and January 6, 2025, the United States has seen 66 confirmed cases in humans and one death.
Human Implications
Coleman and her team are particularly concerned about the potential for bird flu getting into animal shelters which could result in large outbreaks, potentially involving humans – similar or worse to what happened in New York City with a different strain of bird flu in 2016.
There are no reported cases of human-to-human transmission of bird flu, but researchers are concerned that as the virus spreads and evolves, it could become easily transmissible through the air.
“Our future research will involve studies to determine the prevalence of HPAI and other influenza viruses in high-risk cat populations such as dairy barn cats. Our research seeks to protect people and our vulnerable pet cats from the emerging threat of H5N1,” said Ian Gill Bemis, coauthor of the paper and doctoral student studying bird flu in cats.
Reference: “Avian Influenza Virus Infections in Felines: A Systematic Review of Two Decades of Literature” by Kristen K Coleman and Ian G Bemis, 7 May 2025, Open Forum Infectious Diseases.
DOI: 10.1093/ofid/ofaf261
Funding for this project was provided by the University of Maryland Baltimore, Institute for Clinical & Translational Research (ICTR) and the University of Maryland Strategic Partnership: MPowering the State (MPower) to KKC, as well as discretionary funding from the University of Maryland School of Public Health, Department of Global, Environmental, and Occupational Health to KKC.
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17 Comments
Looks like the cat ladies in masks to this day will now be masking their cats.
Unfortunately, there’s no credibility left, whatsoever after the last flu, which caused a massive economic crash, a suicide wave and basically wrecked our society, all because dying people were dying faster.
I love my cat and I’m not wearing a mask or taking a shot. Good luck
Good plan
This shouldn’t be happening……unless the virus has been modified. By humans?
What does our
CDC say?…..Oh!, never mind.
If our government would stop weaponizing these viruses, there wouldn’t be a problem.
The title of the article says that the bird flu has a 90% mortality rate in cats. The article however says “researchers uncovered 607 cases of bird flu in cats around the world, including 302 deaths. ” I’m not a mathematician, but 302/607 = 0.50 (50%) – not 90%. It’s this type of sensationalist BS that makes me read every article with extreme skepticism. It’s become commonplace in a huge numbers of academic papers nowadays for the conclusions to differ radically from what the data says.
The text says that the most deadly strain of bird flu has the 90% mortality rate, which means the other strains aren’t as deadly. Therefore the headline is misleading.
oh please is there a method to infect the deer population?
I’d rather infect the politician population.
Good.
I suspect this will mostly affect feral and “outdoor” cats.
Keep your zoonosis-spreading felines INDOORS away from screens and children’s sandboxes and neighbors’ flower beds..
Yes, it’s amazing the chaos and death that can be created with “gain of function”, but hey, it pays well, right? So, what’s next? More poisons for humans masquerading as vaccines, again? Good luck with that, you already blew your load. Nobody believes you anymore.
Ah well; its not Smallpox which had been vaccinated out of existence, barring specimens in assorted military laboratories, by 1980. I gather that poliomyelitis is spreading once again, thanks to parents failing to vaccinate their children against it. Same thing with measles.; idiots at work.
Of course it’s killing them at 100% rate. If it killed them at 50% rate they wouldn’t be dead.
Whats that about zombie cats? Now that is something I can believe!
It’s really hard to believe all the species-specific hatred being spewed here in the comments. Very sad. Very disappointing. And very pathetic.
Omg! Unicorn science and fear mongering! They same scientists are the ones that lied about covid 19. Total BS. The swine flu wasn’t even a thing, they made that up. This is the first steps in getting laws to take away individuals the right to have their own source of food and grow food. They targeting cats unfairly because of over population from irresponsible pet owners. I call BS!
F science and all that, what has it even done for me? First they tell me having kids with my sister was a bad thing and now they say my son got his autism from me! BS!!!