How Risky Is the Bird Flu in Cats?

The U.S. Department of Agriculture has confirmed 130 cases of H5N1 avian influenza, commonly known as bird flu, in domestic cats. The cases are spread across 23 states, including Illinois. Dr. Leyi Wang, a virologist at the College of Veterinary Medicine, recently identified H5N1 in a cat at the college’s Veterinary Diagnostic Laboratory. He discussed how cats contract bird flu, what symptoms to look for and precautions pet owners can take in an interview with News Bureau biomedical sciences editor Liz Ahlberg Touchstone.

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Why is bird flu in cats a concern?

Previously, H5N1 had limited infection in mammals. However, the new H5N1 involved in outbreaks since 2022 mutated and acquired the capability to infect different mammal species including domestic and wild cats. So far, 43 types of mammals have tested positive for bird flu in the U.S., with domestic cats being the highest number. And with a respiratory virus like influenza, we know many more are infected than have been diagnosed.

Domestic cats are companion animals and have close contact with humans, potentially transmitting viruses to owners. A previous report revealed a cat-to-human transmission of influenza A virus, so H5N1 transmission might be possible as well.

How do cats catch bird flu?

Cats can catch bird flu through drinking raw milk; eating raw pet food containing poultry such as duck, chicken or turkey; exposure to or consuming dead birds outside; contact with contaminated clothing, especially shoes or boots; or exposure to wild waterfowl. At the Veterinary Diagnostic Lab, we just had a case of bird flu in a cat who lived on a poultry farm. It is highly possible the cat caught it through exposure to dead chickens outside. We also tested a wild rat found on the property, and it was positive for H5N1 as well.

Infected cats could spread virus to other cats and possibly other pets in the household or even humans.

What are the symptoms of bird flu in cats?  What should a cat owner do if they are concerned their pet may be infected?

Bird flu H5N1 infections in cats are usually serious and life-threatening, with a high mortality rate. Infected cats show severe clinical signs such as lethargy, fever, loss of appetite, difficulty breathing, discharge from the eyes and nose, and neurological issues like tremors, seizures, incoordination or blindness.

Cat owners should contact their veterinarians if they are concerned their pet has contracted bird flu. Tell the veterinarian if your pet has been exposed to raw meat, raw milk, backyard birds or wild waterfowl. Unfortunately, only supportive care is available for cats with bird flu, and no antiviral drugs are yet available. 

What can pet owners do to protect themselves, their cats and other animals in their care?

Currently, there is no available vaccine for H5N1 in cats or other pets. To reduce risk, pet owners should prevent their cats from eating birds or other wild animals. Do not feed cats raw meat or raw milk. Keep pets away from wild birds, poultry and cattle. 

If you work with animals, wash your hands well after interacting with poultry, livestock or animals outside the household. I also would suggest changing clothing and shoes after interacting with animals or birds with unknown health status, before interacting with your own pets.

To contact Leyi Wang, email leyiwang@illinois.edu.

Feature photo by L. Brian Stauffer