Cats As Potential Vectors/Mixing Vessels for Novel Flu
#18,260
We've known for 20 years that cats (and to a lesser extent, dogs) are susceptible to a variety of avian flu viruses (see 2015's HPAI H5: Catch As Cats Can), and that on rare occasions they can even transmit the virus to humans (see EID Journal: Avian H7N2 Virus in Human Exposed to Sick Cats).
Since H5N1 arrived in North America in 2021, we've seen scattered reports of HPAI in American cats (see here & here) - as well as larger outbreaks from other countries (see Poland & South Korea).
Due to the risks of exposure, last April the CDC released Guidance for Veterinarians: Evaluating & Handling Cats Potentially Exposed to HPAI H5N1.
Until last May, the USDA wasn't including infected cats on their wildlife with H5N1 list, but that changed with the unexpected detection of HPAI H5 in dairy cattle, and reports of farm cats falling ill with the virus.
On May 30th the USDA added 16 cats to the list, going back to March. Since then, that number has expanded to 37 cats, although this is almost certainly an undercount:
Two weeks ago the state of Colorado released some details on 6 feline infections, of which only one was connected to a dairy barn.
- Two of the 6 were indoor only cats, with no known exposures to the virus
- Three of the 6 were indoor/outdoor cats, which may have hunted mice and/or small birds
- Five of the 6 presented with respiratory symptoms and neurological impairment
With the amount of environmental HPAI expected to increase with this fall's migration (see Something Winged This Way Comes), there are increased opportunities for companion animals to be exposed in the months ahead.
With that in mind, yesterday Animal Health Canada and Companion Animal Surveillance System issued the following guidance to veterinarians on HPAI in cats.
If your domestic animals (e.g., cats or dogs) go outside and could potentially eat or be exposed to sick or dead birds infected with bird flu viruses, or an environment contaminated with bird flu virus, they could become infected with bird flu. While it's unlikely that you would get sick with bird flu through direct contact with your infected pet, it is possible. For example, in 2016, the spread of bird flu from a cat to a person was reported in NYC. The person who was infected [2.29 MB, 4 pages] was a veterinarian who had mild flu symptoms after prolonged exposure to sick cats without using personal protective equipment.
If your pet is showing signs of illness compatible with bird flu virus infection and has been exposed to infected (sick or dead) wild birds/poultry, you should monitor your health for signs of fever or infection.
How to prevent spread
As a general precaution, people should avoid direct contact with wild birds and observe wild birds only from a distance, whenever possible. People should also avoid contact between their pets (e.g., pet birds, dogs and cats) with wild birds. Don't touch sick or dead birds, their feces or litter, or any surface or water source (e.g., ponds, waterers, buckets, pans, troughs) that might be contaminated with their saliva, feces, or any other bodily fluids without wearing personal protective equipment (PPE). More information about specific precautions to take for preventing the spread of bird flu viruses between animals and people is available at Prevention and Antiviral Treatment of Bird Flu Viruses in People. Additional information about the appropriate PPE to wear is available at Backyard Flock Owners: Take Steps to Protect Yourself from Avian Influenza.
For more on companion animals and avian flu, you may wish to revisit:
