Thank you for your question. In short, dog's generally only lick their penises excessively if there is something bothering them. For this reason I would definitely recommend getting your boy to your local Veterinary clinic for a good old physical examination (of everything - but particularly his genitals). More often than not, dogs that excessively lick their penises have a discharge either from their penis or prepuce. The normal dog should have no discharge, although a small amount of whitish-yellow "smegma" can accumulate around the preputial opening, and is not considered clinically significant.
There are many potential causes for your dog excessively licking his penis. These include:
Disorders affecting the prepuce, including cancer, trauma, foreign body or inflammation of the penis/prepuce (balanoposthitis).
Disorders of the urethra, including cancer, trauma or stones (calculi).
Disorders of the urinary bladder including infection, calculi, inflammation or cancer.
Disorders of the prostate, including infection or inflammation of the prostate (prostatitis), cancer, enlargement (hyperplasia), cyst or abscess.
Bleeding disorders (coagulopathies) including decreased platelet count (thrombocytopenia) or ingestion of rat poison
Urinary incontinence (inability to hold urine) secondary to an ectopic (abnormally placed) ureter or improperly functioning sphincter (tissue that acts like a door, controlling the release of urine).
The presence of a discharge from the prepuce ('preputial discharge) most often suggests an underlying problem, ranging from a mild, relatively benign disorder, to a severe, even life threatening disease and for this reason I would recommend a Veterinary visit within the next few days. He or she will carry out a full clinical examination and decide whether further diagnostics are needed and treat the problem as necessary in order to help stop the excessive penis licking!
I hope this has been of help. Please let me know how you get on.
Thank you and please now click ACCEPT.
Dr M D Edwards