Benign Prostatic Hyperplasia

Condition Overview

This is an increase in the size of the prostate gland. The disease is hormone dependent and is influenced by testosterone. Benign prostatic hyperplasia begins in sexually intact males at about 5 years of age and progresses as the dog grows older.

Symptoms

As the prostate enlarges, it gradually expands backward and may eventually obstruct the rectum, causing constipation and straining while defecating. The feces may appear flat or ribbon-like. Defecation is difficult. Fecal impactions are common.

Rarely, the prostate pushes forward and presses on the urethra causing straining during urination. Blood in the urine can be a sign of benign prostatic hyperplasia.

Older dogs are more likely to have symptoms.

All symptoms +

Causes

About the prostate

The prostate is an accessory sex gland in males that completely surrounds the urethra at the neck of the bladder. The prostate produces fluid that is added to the ejaculate when a male dog mates. This fluid provides nutrients and assists in the sperm's movement. The 3 conditions that cause prostatic enlargement are benign prostatic hyperplasia, prostatitis, and cancer of the prostate.

Diagnosis

The diagnosis of prostate enlargement is made by digital rectal examination, during which the size, position, and firmness of the prostate gland is assessed. Ultrasonography provides additional information and may be helpful in guiding a needle into the prostate to obtain a biopsy - a procedure indicated when cancer is suspected.

Treatment

Treatment is not necessary unless the dog has symptoms. Neutering eliminates the stimulus for prostatic enlargement and is the treatment of choice for dogs who are not intended for breeding. A significant decrease in the size of the prostate gland occurs shortly after neutering.

An alternative to neutering is to administer megestrol (Megace), a synthetic derivative of progesterone. Megace decreases the size of the prostate without impairing fertility, but long-term use may cause a dog to develop diabetes mellitus or adrenal problems. Note that estrogens, because of their potentially serious side effects, are no longer recommended for treating benign prostatic hyperplasia.

Prevention

There is no prevention for this condition.

Support

Please contact your veterinarian with questions regarding this condition.