I had this same problem only when my male saw another cat outside.Vet diagnosed displaced
agression syndrome. I tried "calming zone" a plug
in available at pet stores.This mimics "happy cat"
phermones. Worked for a while then he got anti-
depression pills, hated eating those every day, so
ended up getting him declawed.Hated to do it but,his behavior has totally turned around and he
is now (three years plus) the good Buddy he had been before. Hope this helps!

Member 1140814 answered on 11/15/12. Helpful? / 0