I confess that I have *never* heard of this, but Emerson has started biting his toenails. Eww!

I noticed that he has been knawing on his foot, and thought maybe something was bothering him. So I got down to take a peek, and his dew claws are very, very short and a tad ragged.

Does anybody else's dog chew their toenails? Should I be concerned? I am just hoping that he doesn't make them bleed or anything like that.