2 male cats out of the blue hate each other

Question
I have 2 male cats. One is 6 years old the other is 2 years old. I have had them together for 2 years with no problems. They loved each other, played all the time, slept together, etc. All of a sudden, with NO warning, I got home and they were hissing and growling and ready to kill each other. It has been 24 hours since they started and it seems no better. Why or what happend to make them hate each other so much for no reason? There was no move, no Vet apt. nothing was different? Why would this happen and what can I do to make them like each other again?? I am afraid to go to work with them in the house. Oh, the older one has no claws, not by my choice he was adopted and the younger one has his claws. Please help!

Answer
Hi Maurine.  It sounds possible that redirected aggression could be to blame.  This happens when cats can't reach the source of what's causing their aggression, so they act it out on a pet or person who's nearby, instead.  Something may have frightened them outside your home, such as another animal they saw outside, or a loud noise they heard, and one or both of the cats redirected their aggression onto the other.  Often, the situation resolves once the confusion dies down, but sometimes trust is broken by the seemingly unprovoked attack, and it can lead to longer-standing aggression.  The best way to deal with this is to completely separate the two cats, usually for at least a couple of days.  Right now, they're fearful of each other, and a total break from one another will give them some time to relax.  Then, start to reintroduce the cats slowly, and separate them again if they show signs of aggression.  It may take a couple of weeks before the cats are able to be left together alone.  Remember that one fight could undo all the progress that you make, so it's better to take things a little too slowly than to rush.

It may be a good idea to use a product called Feliway right now.  I use the plug-in diffusers in each room in my house, and I know by my cats' behavior when the product runs out without even checking.  It helps with anxiety-related aggression that much.  You can buy it at pet stores, online and through some vets, and learn more at www.feliway.com