When bringing an outdoor cat inside with other cats, what contagious diseases do I need to be aware of? I know I can test for FeLV and FIV. All of my indoor cats have herpes and calici virus so that isn't really a concern. I don't vaccinate any of my indoor cats for panleukopenia (distemper) so that does worry me. I'm concerned about the enteric coronavirus but I don't know if a cat infected with it is something to be really concerned about. My understanding is that the coronavirus is contagious and can cause FIP, but FIP is not contagious. I'm not sure if that's true because I've found contradicting information about that.