By Samantha Bartlett
A studied published in Emerging Microbes and Infection in early January expressed concern for the potential of the evolution of HPAI H5N1 in cats into a more dangerous virus. The University of Maryland School fo Public Health made a 20-year review of bird flew in felines and noted a sharp increase of the incidence of bird flu in domestic cats, versus zoo-kept or wild species of felines, in 2023. HPAI H5N1 has a 67% mortality rate in cats.
In April 2024, ten cats died of HPAI H5N1 in South Dakota. The strain found in these cats was very similar to that found in the local dairy cow population. Scientist are unsure whether the cats were infected through the ingestion of infected birds or if the transmission occurred through exposure to the cattle. Since 2022, 200 species of mammals have shown to be susceptible to HPAI H5N1 including foxes, bobcats, mountain lions, bottle nosed dolphins, coyotes, skunks, opossums, squirrels, racoons, minks, black bears, polar bears, and harbor seals.
Cats currently do not appear to transmit the virus to people and the virus does not tend to spread from person to person. However, scientists note that only a few changes need to occur for the virus to be suited to transmission among humans. The virus sheds in bodily fluids such as saliva, nasal secretions, and feces. Cats are more likely to get the virus from a sick human than a human is to get it from a cat.
Cats can become infected through the consumption of raw milk or meat. They can also contract the virus from exposure to infected wild birds and dairy workers. Symptoms include neurologic signs such as ataxia, circling, tremors, seizures, and blindness. Other symptoms include lethargy, discharge form eyes and nose, sneezing, coughing and respiratory difficulties.
The College of Veterinary Medicine at Cornell has issued guidelines for testing cats for HPAI H5N1 along with guidance for monitoring shelter and community colonies at https://www.vet.cornell.edu/animal-health-diagnostic-center/about/news/testing-cats-highly-pathogenic-avian-influenza-hpai-h5n1-ahdc.
The AVMA also has guidance on monitoring and managing cats with suspected HPAI H5N1 at https://www.vet.cornell.edu/animal-health-diagnostic-center/about/news/testing-cats-highly-pathogenic-avian-influenza-hpai-h5n1-ahdc.
