If a female cat sprays once, it might be a fluke--some territorial thing that can be overlooked because she did it outside. If it happens again--this time inside--that could mean trouble.
Yesterday, I had some repairmen in the house and Minnie was just going apeshit, totally freaked out and running all over the place looking for escape or a hiding place or something. She did zip outside once when a repairman went out to look at something, but she stopped dead in her tracks because there was a truck and a bunch of guys doing noisy things in the alley. She was caught between a rock and a hard place! She reluctantly went back into the house and resumed running hither & yon.
Sometime after the repairmen left and I went off to work (so I could pay for said repairmen), Minnie sprayed a bag of (non-smelly) trash I'd left in the kitchen to take out later. And I didn't discover it until this afternoon, when I finally got around to dealing with the trash. I'd wondered why she was sniffing the kitchen floor so intently last night.
It gives me the heebie-jeebies to think I tracked through cat pee in the kitchen and maybe trailed it all through the house. *shudder* Needless to say, I mopped the kitchen thoroughly today after I got that trash bag out...and the rug next to it, which scored an indirect hit. The rest of the house, I'm not going to think about. I don't smell any cat pee, anyway.
OK, so now I have a new cat rule: When Minnie gets so extremely freaked out like that, PUT HER OUTSIDE, at least until the "danger" is past and she's maybe done her spraying on the fence. Because, apparently, spraying is her new I'm-totally-unhinged-with-fright reaction.
It really makes me wonder what I'm going to do with her next March or April when Bro-in-law & Sis & I start demolishing my bathroom to remodel it.