From Fowl to Feline: The Evolution of Bird Flu

By Christina P. Hooton

Although cats are said to have nine lives, that superstition won’t protect them from a new potential health threat. The highly pathogenic H5N1 avian influenza has been infecting and killing cats, according to a Science News article. This latest strain of bird flu has been circulating since 2021, mostly affecting wild birds and poultry in the United States. Mammals have not been spared from the virus with reports of goats, dairy cattle, and alpacas falling ill as well.

Scientists can examine these latest developments to try to predict how the virus will evolve and determine whether it will ever mutate enough to spread between humans.

Look at What the Cat Dragged In

For outdoor cats who enjoy catching birds, this is bad news. Even if a cat doesn’t consume wild birds, they can become infected just by coming into contact with them. And cats who are fed raw meat diets, particularly raw poultry, are just as exposed. Water, footwear, or equipment contaminated with bird droppings pose a threat, as well as raw milk that hasn’t been pasteurized to kill bacteria and viruses.

There are no bird flu vaccines for cats, so prevention is the best medicine. Experts advise keeping cats inside and away from birds. They recommend cleaning shoes and disinfecting surfaces that come into contact with bird droppings. Symptoms to look for in cats include stiff body movements, wobbliness, circling, runny noses, and blindness.

Occupational Hazards

The Centers for Disease Control and Prevention (CDC) reports that sick animals may be able to transmit the virus to people via their saliva, feces, and other body fluids. When the virus is inhaled or gets into a person’s eyes, nose, or mouth, either by breathing in droplets or dust or touching something with the virus on it, an infection can occur.

This means people, especially veterinarians and other professionals, who come into contact with animals who are suspected or confirmed positive for H5N1 should take precautions.

An Evolving Situation

Currently, there is a low risk of pets, farm animals, or wild animals infecting people.

However, viruses mutate as they replicate. They make mistakes in the copies they create, leading to new variations in the virus’s characteristics, such as transmissibility.

According to a May 2024 CDC report, the genetic sequencing of a bird flu infection in a Michigan dairy farmer showed that the virus had evolved to be more likely to infect humans, a sign that the virus is changing.

Although there’s no indication that the virus is sophisticated enough to spread between humans yet, this is a situation health officials will certainly be monitoring.