I recently brought my 9 month old kitten back from the vet's after she was spayed, and now my older cat hisses, growls and acts like a feral monster towards her. He gets so vicious that I fear he will attack her. Why does he act this way when just last week they were friendly and playful towards each other. He was neutered when he was 6 months old and is now 7 years old.
Answer by bookay at 3:40 PM on Jan. 27, 2009