My cat has a bald belly!

United States
September 29, 2008 3:10am CST
One of my cats has a bald spot on his belly. He hasn't always had it, he used to have hair there. Some time ago, I don't remember how long, we noticed he had a little bald spot. Well, it is getting bigger. The skin doesn't look irritated or anything. And he seems perfectly healthy. But what would be causing him to lose hair there? Kelly