I got back from taking my dog for a walk earlier, and on the return trip, he was hobbling.  He was picking up his left foot like it was hurt.  I heard no yelp or whimper.

When we got home, where it was light, I looked at his paw, and it was bleeding.  I thought it was something worse than that, since he is getting rather old.

I'm not a vet, and I couldn't see anything stuck in his paw.  He seems a little irritated right now.

My main question here is, do I need to worry about the paw getting infected, or should he be able to clean it himself?

I would clean it with some hydrogen peroxide if it were my dog.

Dogs are wimps.

Just clean it out and he'll be fine.

Just did.

I did the hydrogen peroxide, then cleaned it off with water.  Don't want him licking any of that stuff up.

Quoted: Don't want him licking any of that stuff up.

After your dog licks his balls, sniffs other dogs rears and eats cat shit, you're worried 'bout him licking peroxide?