That looks like an infection to me. Doesn't look too serious yet, so I guess it's your call if you'd rather go ahead and talk to a vet or try doing diluted betadine soaks.
If you do that, it might be good to put him in a tub with just plain water for a minute or two first so he can get a drink, and supervise to make sure he doesn't decide to drink the betadine/water solution.
EDIT: The bits on the side of his neck and under his chin look like blood. However, all the parts on the belly look like mild infection (or potentially a mild burn) to me.
Actually... Now my eyes are playing tricks on me. Use a wet paper towel to wipe him down and see what areas are still red.