One cat all of a sudden hates her brother? What gives...

Ok I’m looking for what’s normal. Lately, Og has decided to put the Northeast [and other regions] into a humid heat wave. Our female siamese cat has decided she does not like us anymore, and this includes her brother. We clip their nails about once every 6 weeks. Usually she growls a little when we do it but this time she lashed out with a hiss I have never heard before. A mean, angry hiss.

Ok so yesterday we bring our male siamese to the Vet, we pack him away in his Sherpa and off we go.

The minute we get back our female cat is hissing away again. No biggy, this has happened before. She retreated to her favorite couch in the basement, and has not been seen since. I figured that when we came home from work today she would be fine. Well we were sorely mistaken. She still doesn’t like him…

How long will this last? This has happened before but not for as long.

Could the oppressive heat be playing in this as well? What say you cat lovers? Is this normal?

I’d say maybe she was crabby for the nail trim, and when a cat comes back from the vet it is not unheard of for another cat to hiss. But…if you think it is abnormal for her, I’d suggest taking her to the vet to make sure nothing is wrong with her.

Cats who are ill often respond by hiding, or by defensive behavior. Second the advice of a vet visit.

And thirded. Although when a cat or dog has been to the vet, they often bring home unfamiliar and frightening smells with them…

Hmm, so she may be physically sick outside of the other cat coming home smelling like the vets office? I think we’ll probably give it a few more days and see what happens. She will have to come up to eat…I hope she does that…

I have two male brothers who have spent almost every second of their lives within five feet of each other, sleeping together all day long. One has urinary problems and once a year or has to spend a few days at the vet with a catheter, and this happens every time he gets home. The vet was unsurprised, and said that he basically just smells differently and the other cat doesn’t recognize him; thinks it’s a new cat.

The bad hissing and lashing usually lasts about two days. He’s still wary for another two days after that, and then they’re fine.

Good to know…

Well this morning, same things…she’s peering aruond the upstairs door and hissing again…As if to say, “…* damn you, you still haven’t got rid of that other cat…”*

Do cat’s really not visibly recognize the other cat? Or is it strictly smell?

It certainly seems that the visual cues (hey, this new cat looks EXACTLY like my brother), would take over. But, having seen this at least six times, the one cat certainly acts like he has never seen his brother of ten years before for a few days.

My brother and his wife have two siamese, brother and sister. Several years ago, the brother (Saaba) was diagnosed with leukaemia. The only thing that prompted the trip to the vet and subsequent diagnosis was that his sister (Taalee) had been hissing at him and avoiding him for a couple of weeks. She obviously sensed/smelled something different about him. The avoidance and hissing/growling continued for several months and intensified every time Saaba came home from chemotherapy treatments.

Well I sure hope that is not the case here. As far as I know he is Leukemia negative…And the hissing started after we got home from the vet.

It’s not unusual for cats to hiss at a housemate who has recently been to the vet. It could last a couple days. However, you described the female as being crabby before the vet visit. Why did you take the male to the vet?

It could be a case of misdirected aggression. She could have been upset or startled by something at some point, even another cat outside, and she is taking it out on those inside. Also, she could have something wrong with her, so I also recommend taking her to the vet. At least maybe she’ll come home smelling like the vet’s office and all will be equal again.
By the way, cats are weird.