Just to make sure it wasn't his nails or fleas that was bugging him, I took him to get his nails clipped again, because they had gotten longer, and also gave him a flea bath. In the end, he still chews his paws.

But, the suggestions that everyone gave has given me some info on what it may be. It may very well be allergies. He's an indoor dog, but he still gets taken for walks outside.

I'll try your option, Freedom, and see if it changes anything.

Thanks everyone.