Thread: Why is my cat losing hair on his behind?

My male cat Perish is losing hair on his back next to his tail. There are also parts on his tail that are turning bald. We are trying to figure out why this is. We tried changing his cat food, it didn't work. We gave him heart worm medication to see if it would kill whatever was making him lose hair and that didn't work either. If you have any idea of how to make my bald behind cat better please tell me.

Sounds like mange.