01/08/2025
Since the U.S. outbreak of avian influenza A (H5N1) in dairy cattle began in March 2024, dozens of cats are known to have contracted the virus, including barn and feral cats, indoor cats, and big cats in zoos and in the wild (e.g., mountain lions, tigers, leopards, and bobcats). Cats were already known to be susceptible to the H5N1 virus, with several feline cases linked to poultry or wild bird exposure before the cattle outbreak began.
How do cats become infected?
Recent investigations implicate food as a source of infection for cats, most often unpasteurized milk and raw or undercooked meat (e.g., poultry). Other potential sources include:
- Raw colostrum and other unpasteurized dairy products (like cream)
- Exposure to infected wild birds or poultry
- Exposure to people who work on affected farms and to their clothing or other fomites
What are the clinical signs of H5N1 in cats?
Illness may start with loss of appetite, lethargy, and fever, then quickly progress, with cats exhibiting:
- Neurologic signs (e.g., ataxia, circling, tremors, seizures, or blindness)
- Severe depression
- Copious oculonasal discharge
- Other respiratory signs, including tachypnea, dyspnea, and possibly sneezing or coughing
What should cat owners do if H5N1 is suspected?
To play it safe, cat owners should:
- Call their veterinary clinic—before taking cats in to be seen—and describe any clinical signs they have noticed so that the veterinary team can be ready when the patient arrives.
- Limit their cat’s contact with immunocompromised individuals if any exposure to the virus is possible.
- Protect themselves and others from influenza
- Monitor their family and other animals that might have been exposed for signs of illness, and report any human illness to their local public health official.
How can H5N1 infection be prevented in cats?
Cat owners and caretakers are urged to follow these tips:
- Refrain from feeding cats any dairy products or colostrum that have not first been pasteurized or thoroughly cooked to kill the virus.
- Thoroughly cook meat before feeding, and avoid feeding raw meat-based treats or diets.
- Keep cats indoors to prevent exposure to birds and other wildlife.
- Avoid contact with sick or dead birds and other wildlife yourself.
- Keep cats away from livestock, poultry, and their environments, especially in areas with known H5N1 outbreaks.
- Take steps to prevent contact between captive big cats and wild birds (e.g., covering enclosures with netting and removing bird attractants nearby) in areas where H5N1 is circulating.
- Thoroughly wash your hands after handling your cat and after any encounters with poultry, livestock, or wild birds and other animals.
- Change your clothes and shoes, and thoroughly wash any exposed skin, after interacting with sick or dead animals that may harbor the H5N1 virus, and before interacting with your cat.
Immediately contact your veterinarian if you notice signs of H5N1 or think your cat might have been exposed to the virus.
