For Max! That looks a little irritated. He could have an infection or it could be some type of mass. The best thing would be to have your veterinarian take a look at it to determine the exact cause and the best way to treat. He may need an antibiotic and an anti-inflammatory. If you can't take him to a vet, then you could bathe him with a medicated dog shampoo and apply an antibiotic cream and see if it resolves.