We just noticed our cat has lost all the hair on her stomach and there is a blister-type sore there. Could a heated cat bed cause hair loss like that? It's a regulated temperature and doesn't feel too hot at all, but because she lives in the garage (husband's allergic), she stays in it all day during the winter. She's eating and drinking well and hasn't seemed to lose any weight. She seems healthy and alert. There's no hair loss any where else.

Any thoughts on what could be causing this?

If she has gotten into any type of fight with another cat or even injured that spot, she will lick and lick until all of the hair surrounding it is gone. It may just be from a small injury and not the cat pad at all.

Could be ringworm, as well. Could be a lot of things. How bad is it? Worth a vet visit?

My younger cat had done this as well. She lost it on on her belly as well as her rear. I had an appointment to take her into the vet to get fixed anyway, and had the vet check her out. She said she had fleas, and they bit her belly so she was licking the sores, which made the hair quit growing. I hadn't even realized she had fleas because she wasn't itching herself & her hair was so thick that I couldn't see the fleas. The excessive groming didn't alarm me either because she's ALWAYS grooming herself.

Thanks everyone for your great suggestions! I decided to just be on the safe side and take her to the vet.
Thanks again!:D

Just curious... what did the vet say?

We have just discovered the same thing with a 15 year old cat and he was put in the garage because of little box issues and lies on a heated pad all day so your comment really got me thinking. He is fat and lazy and lies all day on one of those pads. Did you ever find anything out?

I'm pretty sure it occurred because our cat slept on the heating pad all day and night as well. When summer came and she no longer needed the heating pad, her hair all grew back. The next winter we switched to a heat lamp(not placed too closely) for her to sleep underneath. She did much better with that.