Cat Aggression

We have two cats, both female and spayed - one 6 yo (Lucky) and one 3 yo (Biscuit). They have always gotten along well with each other until the last two months or so - we took the younger one for a vet visit where she was handled more than usual by the Vet, and when we got home, Lucky hissed and ran from Biscuit. This led to Biscuit consistently chasing Lucky - if Biscuit isn't chasing, Lucky is hissing which starts Biscuit chasing. We have been keeping them separate since this started, and tried the cage approach (keeping one in a cage in the middle of the livingroom floor for a little while each night) but when Lucky was caged and hissing, Biscuit would attack the cage, and if Biscuit was caged, Lucky wouldn't come into the room. We tried giving them treats them when they are together, and also tried spraying Biscuit with water to stop her from chasing Lucky - all without significant success. Now we only let them out together at night for a round of chasing and hissing (some rounds of which have resulted in small scratches to the paws and face of both cats) - until Lucky hides, then all is fine until she tries to come out and join the rest of the family...when we go to bed, we shut Biscuit in a spare bedroom for the night and most of the next day until we get home. Any other suggestions for reintroduction? The Vet recommended a spray that they use to calm aggressive cats at the office that's based on cat pheremones(?!?) - has anyone used this with any success? Any other suggestions?

They are talking about Feliway. It has worked well for many people I know and have talked to. You have to use it as directed though. You can also make them smell the same. Rub both with the same scent. I think it was Gaye who said she uses vanilla. Also you can try giving them both Bachs rescue remedy which is found in health stores. You can give it to them in water or give them a few droppers a day.

Thanks for the reply - do you know where to find Feliway? I will try the Bachs and see if that helps. Its just really strange that they got along for 3 years and now they seem to absolutely want to kill each other! Hopefully one of these will help. Thanks again.

The feliway most vets carry, but I know if you do a search on the net you will find a retailer. Cats are funny this way. Something triggered it and you may never know what it was.