I'd say if there's nothing you can 'feel' on the inside of his cheek, that I'd go with 10-14 days of antibiotics. I once had this with a male bulldog, who ended up needing surgery to remove the lump that would knock down with a/b's and then get large/hard again after meds stopped...turned out to be a foxtail embedded in the salivary gland in his cheek! Hope this isn't that serious.
