cats behavour problem

Question
my 10 month old cat Kenya had an accident rspca found her i picked her up and took her to the vet she was there two days. when i brought her home. her sister indie and her are scared of each other hissing acting very aggressively. kenya even tryed to attack indie today. they where so close always crying for one another. laid and  slept together always. i dont understand whats happened. i have to separate them especially as kenya is so much smaller with a very badly damaged leg. i dont know what to do.

Answer
Adele,

That is normal behavior towards cats that come home from the vet. Cats go by smell and not by sight in recognizing other cats (with humans, they go by voice...not by sight). Your cat brought home MANY different smells from the vet: anesthetic, medicinal smells, and smells of other cats...all clinging to her fur and skin. The sister thinks she's another cat because she doesn't smell the same! Things will settle down  when the smells are gone from the cat that went to the vet.

As the cat grooms herself she will be replacing her regular scent. You can keep them separated if you want until the smells are gone from her fur. It will take a few days or longer.

You can also rub the cat who did not go to the vet with a towel, then rub the cat who did go to the vet with the same towel to transfer familiar smells but do not do it the opposite way because you will then be transferring the vet's office smells to the other cat.

A trick that I've heard a lot of people use in that situation (though I have never tried it) is to put a drop of vanilla on each cats forehead so they smell the same.

Try giving both cats a special treat, like a can of tuna. Feed them next to each other so that being together is a pleasant experience and not a negative one.

There is also another cat calming product that you can add to her food or water that reduces anxiety called Bach's Rescue Remedy. It is available on-line and in health food stores. Here is a link about it: (copy and paste, or type the whole links into your address bar)
http://www.bachflower.com/Pets.htm

Things will settle down once the smells and/or bandages are gone from the cat that went to the vet.

Tabbi