my cats just started fighting

Question
i have two girl cats that have been living together for three years now, kallie picks on aj every once in a while in a sort of playful manner, but this morning they freaked out and started really really fighting and i have had to keep them separated all day.  from trying to get them together i noticed that kallie is the more aggressive one, but there was one time that aj was the aggressor.  im not sure if it's a territorial thing or if they saw an animal outside that freaked them out [because sometimes they fight real quick when they see a oppossum or something] but i dont understand how they can seem like strangers to eachother after three whole years. do you know what's up with that?

Answer
Hi Katie,

I have 13 cats that have been together for a long time. The same happens in my household. One will pick on another and then there is a major cat fight that i have to break up. Little things can set it off. If they have fought before from seeing something outside then i would say that was the catalyst. They will settle things out. If you wish to calm things down get a product called Feliway. It acts as a kitty tranquilizer. Just spray it around the rooms your cats are in and they should be fine. Good luck and let me know what happens.

Ciao, Karen