I have a one year old indoor cat who is always incredibly affectionate and has never growled or hissed at anything before. I have came home before after petting cats at a friend's or family member's house before and am sure I probably still had their scent on me and she has not reacted at all. However, I saw a stray around my porch this afternoon and went out to see if it had a collar on and pet it. As soon as I came in and walked near her, she started hissing and her hair was standing up everywhere. I changed my clothes and washed my hands and she still would hiss anytime I went near her for a couple of hours. So overall I'm just curious why she reacted so strongly to this cat's scent when she's never done that before. Does it have to do with gender/breed/hormones?
