Prostate Disease in the Breeding Male Dog

Benign prostatic hyperplasia (BPH) is an increase in the size of the prostate gland. It is the most common prostatic disorder and is found in most intact male dogs >6 yr old as a result of androgenic stimulation or altered androgen/estrogen ratio.

Prostate is the accessory organ in male dogs that completely surrounds the urethra at the neck of the bladder. It 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 prostate gland increases in size and weight with age. During this increase in size, it gradually expands backward and may eventually obstruct the rectum, causing constipation and straining while defecating. The feces may appear flat or ribbonlike. 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.


This condition is hormone dependent and affects the glands and connective tissues of the prostate, causing swelling of the prostrate gland, which then presses against the rectum, making the canal smaller and defecation painful for the dog. 


BPH is due to an age-associated increase in estrogen in the prostate. The ratio between estrogen and androgen is believed to contribute to BPH development in older dogs, as both estrogens and androgens are required for significant prostatic enlargement to occur.


Most dogs don't show clinical signs of this condition but in chronic cases, the signs become apparent as BPH can render the prostate more susceptible to infection from the urinary tract and subsequent development of bacterial prostatitis.


Common symptoms associated with this condition include

Prostatic disease – general


Tenesmus (constipation)

Bloody urethral discharge

Reduction in urination or defecation

Stranguria (straining to void)

Benign prostatic hyperplasia



Prostatitis – acute

Systemic illness (vomiting, lethargy, inappetence, weight loss)

Purulent urethral discharge




Stiff legged gait

Prostatitis – chronic

Recurrent/chronic urinary tract infection


Stiff gait


Prostatic cyst

See type description for BPH (above)

If associated with infection see prostatitis

Prostatic neoplasia


Dyschezia (defective reflex for defecation-painful defecation)

Difficulty with moving rear limbs

Lumbosacral pain (back pain between the ribs and pelvis)

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