Q. Two great indoor cats live with me in my home. They were feral cats that roamed my neighborhood. One large orange cat has apparently adopted us and loves to come by the patio door to visit with my cats. Now that the weather is getting warmer, I like to keep the patio door open sometimes. Can the outdoor cat transmit any illnesses or disease through the screen? Can fleas or any other parasites be transmitted as well?
I am a new cat owner and so I do not know much about how things can be transmitted cat-to-cat. My cats have had rabies shots and some other ones. Thank you for the information!
A. This is a great question and one that I am asked frequently! The common diseases that can be transmitted from one cat to another via aerosol (or as we say in medicine, by fomites) are FRV (feline viral rhinotracheitis), C (calicivirus) and P (panleukopenia).These are the common diseases that we vaccinate against in the FVR-CP combination vaccine so as long as your cats are properly vaccinated, these are not a concern for you.
The other worrisome kitty diseases, such as FeLV (feline leukemia virus) and FIV (feline immunodeficiency virus), require actual cat-to-cat contact for transmission. As long as your indoor kitties and this visitor are not fighting there is little reason to worry about transmission. Another cat disease that is devastating is FIP (feline infectious peritonitis). This disease is spread via a fecal-oral route, which is the feces of one kitty with the virus in it ends up in the mouth of another kitty. This generally occurs if two cats are using the same litterbox and the infected kitty’s feces ends up on the paws of another kitty that then proceeds to clean her paws and becomes infected. Again, this is unlikely in your circumstances.
Transmission of fleas is possible if the cats spend time in the same area. If your visitor remains strictly outdoors then this is unlikely to happen. Still, in areas where there are fleas I generally advise owners to apply a topical flea preventative, because fleas can migrate indoors. If heartworm disease is prevalent in your area, then a heartworm preventative medication is also advised. I think you can safely continue to entertain your visitor as long as you keep him separated from your indoor kitties.