There is a bulge under the dog's anus

There is a bulge under the dog's anus. It may be that the dog has anal adenitis. Anal adenitis is caused by the owner not cleaning the dog's anal glands regularly. Regularly cleaning your anal glands can prevent inflammation and reduce odor. You can take your dog to the hospital for examination and treatment, and your dog’s anal glands should be cleaned regularly in the future. If you don't know how to clean it, ask your doctor.