It may be allergies. My Creamsicle, a short hair orangie, lost so much of her hair that her tail looked like a rat's tail and her back had hardly any hair on it at all. She's now on steroids to alleviate the itching and that's important b/c my vet said that it was like having a bad case of poison ivy. Her hair came out in paint brush clumps. Unfortunately, she's gained a lot of weight on the steroids so she's on diet food now but the poor girl can't itch and lose her hair and groom all day so I had no choice but to put her on steroids. I sure hope you get to the bottom of this so that your kitty can get some relief. Please keep us posted.