here is a very odd behavior,
first good news, our younger 8 month ish stray we adopted (Nami) just got spayed
the weird part about it is chopper's behavior (1 yr neutered male), theyve known each other for about 2 months now and have seemed best of buddies from the start (1 day of hissing, 2 days of "suspicious" looks, then by a week they were grooming each other)
well, we got her back from the vet (she stayed overnight) and brought her back, she was looking pretty sick (she was sedated) and she sort of wobbled out of the cat carrier
chopper however, kept hissing at her, and thought we picked her up at 9 AM (its 1:40 AM the next day now, so its been over 12 hrs) he's still hissing at her... she still looks weak but a lot better, and chopper is still hissing away when he walks by her.
its so weird, all his body language is making him appear scared and not aggressive...
his tail is not fluffed, his back is not rigid, he doesnt get very close to her, he's jumpy and even hissed at us a few times (again no aggressive behavior and even let us pet him as usual and was affectionate as usual).. he's also sitting down with his paws tucked inside him and his tail semi-tucked to the side of him..
its a bit strange, don't know why he's hissing so much and all day, we thought about isolating him from her but she seems to ignore him and he seems to exhibit his normal behavior completely other than turning her way and tossing a hiss at her randomly when he's near her.
oh and he's making a very weird sound too, it almost sounds like he's trying to growl, think lion roar + cat meow put together.. kind of cute almost lol
-confused cat owner