Despite its name, highly pathogenic avian influenza (HPAI) is being detected in more and more species of mammals—including cats, dogs, and humans. 

The disease, also known as H5N1, and its impact have centered on commercial poultry production, but there also are concerns about its detection and spread in companion animals such as cats, dogs, and birds. 

“If you have pets or if you have backyard poultry, keep an eye on them,” says Hemant Naikare, director of the Univeristy of Minnesota Veterinary Diagnostic Laboratory.

Cats and dogs can become infected with H5N1 through a variety ways:
 

• Consumption of unpasteurized milk from infected cattle
• Preying on infected birds and animals
• Eating uncooked poultry, eggs, or beef from infected animals
• Exposure to other animals infected with H5N1
• Exposure to people who work on affected farms and to their clothing or other fomites

Backyard poultry and other captive birds also can contract an infection from interacting with wild migratory birds. As of mid-April, the disease was confirmed in nearly 30 backyard flocks in Minnesota by the state’s Board of Animal Health. 

Research into the disease’s transmission and spread is ongoing, but it remains unknown if H5N1 can be directly transmitted between pets. There is evidence to suggest cat-to-cat transmission in big cats (e.g., tigers), but as of now, not between domestic cats. There is also no known evidence that H5N1 can be transmitted from infected humans to pets. The risk of pets spreading the disease to people is considered extremely low but is not zero. H5N1 is considered low risk to the public, but the risk is greater for those who handle and care for infected animals.

To prevent disease spread, it’s important to follow good hygiene practices when handling animals, their food or waste, and equipment. This includes thorough handwashing and using appropriate personal protective equipment—particularly for those who are immunocompromised. 

If a pet or other companion animal becomes infected with avian influenza, there are clinical signs that owners may observe. 

“If their behavior has changed outside of the norm, such as consuming less water or eating less food, it is usually a sign of a disease or an infection,” Naikare says. 

Other reported clinical signs to watch out for include anorexia, fever, lethargy, discharge from the eyes and nose, respiratory signs due to pneumonia, neurologic signs due to encephalitis, and death in some cases. However, it is important to note that similar clinical signs are often encountered with common respiratory diseases of cats and dogs.

In cats, an H5N1 infection can manifest as a more severe illness, while dogs usually exhibit mild symptoms and have a low mortality rate. The disease hasn’t been detected in dogs in the United States, but fatal cases have been reported in other countries. 

If an animal dies suddenly, the cause of death may be HPAI, and its body should be submitted to the VDL for further testing. Samples such as throat and nasal swabs from live animals also can be sent to the laboratory for testing. Instructions for submitting samples and animal bodies for examination can be found on the VDL’s website. In qualifying cases, the National Animal Health Laboratory Network covers testing costs. 

As scientists and government agencies continue to work to mitigate the disease’s spread, animal owners should continue taking precautions for the health and safety of their pets and themselves. 

“Be more vigilant, make sure you’re following good hygiene practices, and get in touch with your veterinarian if you notice anything unusual,” Naikare says. “Our state Board of Animal Health provides great support, so if you have horses or if you have pocket poultry, they will be able to help you if you see anything that isn’t normal.”