2 cats - 1 just spayed - the other being very aggressive ...?

Question

I have 2 cats ... 1 is just over a year, the other just under. The male cat was neutered when I got him (he's the older & much bigger one). I just took my female to the vet yesterday to be spayed. She came home yesterday afternoon and I confined her to her own room set up with her perch, water, food, etc etc (because I also have a dog that isn't always nice to the cats and I didn't want her hurt). Anyways, I let the big cat come in and see her this morning because he was sitting at the door, like he missed her. I thought, how cute! When I let him in, she went right up to him. He started growling & hissed at her when she sniffed his nose. This cat has never growled/hissed in his life! Even when I brought the little one home the first time. Any ideas why he's acting like this to her?

Thanks in advance!

Answer 1

This happens on occasion when one cat has gone to the vet for anything.  Most of the time it is because of the smell of the vet on the female cat.  I would suggest getting a blanket or towel to rub on the female and then rub it on the male just to mingle the scents.  He should get used to her soon but it may take a few days.  

Answer 2

I had the same thing happen. I had a three year old neutered male who got along with my kitten really well. When I brought home the kitten from being spayed, he hissed a growled for days. It is because he smells like the vet. My vet warned be about it before taking her home and said it was normal. Plus the cone they get doesn't help (if she has one). Not only does she not smell like his friend, she doesn't even look like a cat when wearing the cone.

It should stop after a couple of days when she no longer smells strange.