I have two female cats who have been living together for about three years now. They've always got along very well. Sleeping together, grooming each other, eating together, etc. Two days ago I got one of them spayed (the other was already spayed), and once i brought her home, they've been growling and hissing at each other and they both have decided to hide all day long from one another. The cat who was spayed has already started acting normal (with this exception) so I'm just wondering if this is something that happens a lot, and will it get better?