cat terrified of other cat after being spayed

I have two cat who were best friends. One is a male and the other a female. Recently the female was spayed and ever since the male has hissed and "screamed" everytime he sees her. This has not gotten better with time.

Hmm, I am sure once she came back she smelled different, and that freaked him out. What interaction have they had since?

I'm with Karen, this is typical for the first day or so. Has the issue lasted longer than that? Maybe without all the hormones racing through, she smells like a 'new' cat in his territory?

When will the male be neutered, or is he already fixed?

How long has it been? As mentioned, it's not uncommon for other cats to act oddly toward another cat that came home from a recent vet trip because of the smells, etc.

I have been thruogh this. It's quite disturbing, however they are indeed cats and they will take thier sweet time. May never get over it , but the aggression usually subsides as they eventually become bored and move on :D