Bird flu has been detected in domestic cats across the United States. Are there risks of cat-to-human transmission?
RT’s Three Key Takeaways
- H5N1 Bird Flu Infections in Domestic Cats: The US Department of Agriculture has documented cases of H5N1 bird flu in domestic cats across 18 states.
- Human Risk Low—But Not Zero: Risk of cat-to-human transmission is extremely low, but may increase with prolonged, unprotected exposure to infected animals.
- What Can Cat Owners Do? A University of Illinois veterinary scientist discusses how cats contract bird flu, what symptoms to look for, and what precautions pet owners can take.
Bird Flu Infections in Domestic Cats
The US Department of Agriculture has documented a total of 36 cases of H5N1 bird flu in domestic cats in 2025 (as of April 2nd), according to the department’s Animal and Plant Health Inspection Service (APHIS) database.1 Since 2023, a total of 97 domestic cats have been infected with H5N1 bird flu.1
Of the 97 cases since 2023, California has reported the most at 20, followed by Oregon (14), Colorado (9), South Dakota (9), and four other states with at least six cases.
Cats are reportedly vulnerable to severe disease once infected, with a mortality rate of up to 50-70%.2-3 A July 2024 case report from the CDC documented a fatality rate of ≈50% in cats infected with H5N1 after they consumed raw (unpasteurized) colostrum and milk from infected dairy cows. Scientists warned the similarities in clinical disease between these cats and others infected via wild birds “raise new concerns regarding the potential for virus spread within mammal populations.”2
Previously, H5N1 had limited infection in mammals, but mutations in the virus have allowed it to infect different mammal species including domestic and wild cats, according to Dr Leyi Wang, a clinical associate professor of Veterinary Clinical Medicine at the University of Illinois College of Veterinary Medicine.
“So far, 43 types of mammals have tested positive for bird flu in the US, with domestic cats being the highest number,” Dr Wang said in a news release.4 “And with a respiratory virus like influenza, we know many more are infected than have been diagnosed.”
The H5N1 infections in domestic cats, spread across 18 states, have raised concerns over the danger of disease spread in household pets, and the possibility of cat-to-human transmission of avian flu, similar to human exposures from other animals like poultry and dairy cows.
According to the CDC, most H5N1 infections in domestic cats have occurred at avian influenza A(H5N1)-affected farms, where they have been exposed to infected poultry, infected dairy cows, or wild birds.5
Dr Wang, who recently identified H5N1 in a cat at UI’s Veterinary Diagnostic Laboratory. explained, “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.”4
Prior to February 2025, documented cases of H5N1 bird flu in domestic cats were limited to outdoor-only animals. However, according to a recent CDC Morbidity and Mortality Weekly Report (MMWR), highly-pathogenic avian influenza A(H5N1) virus was detected in two indoor-only domestic cats for the first time. The animals, which suffered respiratory and neurologic illness, lived in homes of dairy workers but had no known direct exposure to HPAI A(H5N1)–affected farms, the CDC reported.6
The agency says, while rare, it is possible for indoor-only cats to be infected with avian influenza virus, likely through contact with infected animals or people, or contaminated surfaces like clothing.5
According to the American Veterinary Medical Association (AVMA), it’s unclear whether cats infected with H5N1 bird flu can infect other cats, but “that possibility cannot be dismissed.”7
Human Risk Low—But Not Zero
Since the current H5N1 outbreak began in March 2024, 70 humans have been infected with the virus in the United States, according to data from the CDC.8 One death was reported in January 2025, a 65-year old man in Louisiana with underlying medical conditions who contracted the virus through exposure to wild and backyard birds.9
Transmission vectors for those individuals were exposure to diary herds/cattle (41 cases), poultry farms and culling operations (24) and other animal exposures like backyard flocks, wild birds, or other mammals (2), according to the CDC.8
To date, there have been no reports of H5N1 bird flu transmission from cats to humans, but that possibility is not without precedent.
The first ever cat-to-human transmission of influenza A(H7N2), an avian-lineage influenza A virus, was reported in 2016.10 In that case, a veterinarian contracted the virus during an outbreak of H7N2 among cats in New York City animal shelters. Researchers tested 165 humans with exposures to infected cats and reported only one case, concluding “risk for cat-to-human transmission was low.” 10
In its February 2025 report, the CDC said, that although rare, indoor cats infected with H5N1 “might pose a risk for human infection.” The agency scientists wrote: “Presumed cat-to-human transmission of low pathogenic avian influenza A(H7N2) virus in an animal shelter in 2016 suggests that exposure to cats infected with HPAI A(H5N1) virus might also pose a transmission risk to humans.”6
Despite the low risk of transmission, the CDC urges precautions for certain occupations with regular exposure to cats.5 “Veterinarians and veterinary staff in field and clinical settings who are working in close contact with cats who are suspected or confirmed-positive for avian influenza A(H5N1) virus infection should take precautions to prevent direct contact with an infected animal without personal protective equipment (PPE),” the CDC says.5
What Can Cat Owners Do?
The American Veterinary Medical Association (AVMA) says clinical signs of H5N1 in cats include: loss of appetite, lethargy, and fever, then other respiratory signs, including rapid or difficulty breathing, and possibly sneezing or coughing, neurologic signs (such as ataxia, circling, tremors, seizures, or blindness), severe depression, and heavy discharge from the nose and eyes.7
The organization encourages pet owners to play it safe if they suspect their cat is infected by notifying a veterinary clinic prior to arriving with a potentially infected cat, monitoring family members for symptoms, limiting the cat’s contact with immunocompromised individuals, and following CDC recommendations.7
Dr Wang echoed those sentiments. He cautioned pet owners to keep pets away from wild birds, poultry and cattle, to refrain from feeding cats raw meat or raw milk.4
For animal workers, he encouraged them to wash their hands well after interacting with poultry, livestock or animals outside the household, and to change clothing and shoes after interacting with animals or birds with unknown health status prior to interacting with pets.4
“Currently, there is no available vaccine for H5N1 in cats or other pets,” said Dr. Wang. “Unfortunately, only supportive care is available for cats with bird flu, and no antiviral drugs are yet available.”
References/Sources
- https://www.aphis.usda.gov/livestock-poultry-disease/avian/avian-influenza/hpai-detections/mammals
- https://wwwnc.cdc.gov/eid/article/30/7/24-0508_article
- https://www.vet.cornell.edu/departments-centers-and-institutes/cornell-feline-health-center/health-information/h5n1-avian-influenza-and-your-cat
- https://vetmed.illinois.edu/2025/04/07/how-risky-is-the-bird-flu-in-cats/
- https://www.cdc.gov/bird-flu/risk-factors/bird-flu-in-pets.html
- https://www.cdc.gov/mmwr/volumes/74/wr/mm7405a2.htm
- https://www.avma.org/resources-tools/animal-health-and-welfare/animal-health/avian-influenza/avian-influenza-h5n1-cats
- https://www.cdc.gov/bird-flu/situation-summary/index.html?cove-tab=0
- https://respiratory-therapy.com/disorders-diseases/infectious-diseases/influenza/louisiana-reports-first-us-h5n1-bird-flu-death/
- https://academic.oup.com/cid/article/65/11/1927/4049509
