A. If it has been slow growing it could be a tumour, if it has come up quickly it could be an abscess or a haematoma. It needs to be seen by a vet and possibly a fine needle aspirate performed to find out what is causing the swelling and then it can be treated correctly. You can try tempting to eat with some cooked chicken served warm as this smells stronger and can encourage eating. Shread it finely so that he doesn't have to chew if this is causing pain or discomfort.
Your account has been reactivated.