I would call the vet, they will probably give you some antibiotics. They will probably wrap them up I would assume. I would also try to put each paw in a big bowl of cold water to get any lose sand or concrete stuff out of the wounds. These are just my ideas. I don't recommend putting anything on them except cold water. Also it would hurt to just call the vet. Sometimes they will tell you how to take care of it without having to go in to have it looked at.