Pathology of the Prostate Gland in Animals: Prostatitis, Prostatic Hyperplasia and Adenocarcinoma

Pathology of the prostate gland is not common in all animals except the dog in which prostatitis and hyperplasia of the prostate are common.

Tumors of the prostate are uncommon. Senile atrophy of the prostate in intact male dog is rare.

Prostatitis in Dogs

Prostatitis in the dog is often associated with hyperplasia of the gland. It is probably due to an ascending infection through the urethra but may occur secondary to hematogenous infection or even descending infections.

A wide variety of organisms have been isolated from infected glands including B. canis, E. coli, Streptococci and Proteus.

Acute prostatitis in the dog is a diffuse or local suppurative inflammatory reaction with a tendency for abscess formation.

Bacteria, leukocytes, and blood are frequently found in the urine or observed at the preputial orifice.

This should be differentaiated from a balanoposthitis.

Acute prostatitis may be painful and characterized by constipation, an arched back, elevated temperature and pulse rate, occasionally anorexia and vomiting, and possibly a leucocytosis. Palpation of the infected gland per rectum causes pain and “splinting” of the abdomen.

Chronic prostatitis is occasionally observed. The treatment of prostatitis is frequently successful.

Parenteral injections of broad range antibiotics are indicated over a prolonged period.

If the ordinary antibiotics do not control the infection, cultures of the prostatic secretions may be made and the antibiotic sensitivity of the causative organism determined.

If prostatitis is due to B.canis the prognosis is poor. Low doses of X-radiation may be of value in reducing the inflammation in some cases.

Clinical prostatitis in the bull and boar is rare and may be caused by B. abortus or suis.

Prostatic Hyperplasia

Prostatic hyperplasia is present in most dogs over 5 years of age that have not been castrated. The condition is probably due to an endocrine imbalance with an excess of testosterone being secreted which causes an enlargement and hyperplasia of the gland.

Adenocarcinoma of the Prostate

Adenocarcinoma of the prostate in the dog is observed only rarely in dogs over 10 years of age. Persistent straining at the time of defecation was characteristic of all cases.

Pain was commonly observed symptom. Adenocarcinoma of the prostate results in a nodular asymmetrical enlargement of the gland.

The tumor may vary in consistency from very hard to soft and is slow to metastasize.

Castration, estrogen therapy and radiation therapy are of definite value in man in delaying the growth of the tumor even though metastasis has occurred.

Prostatectomy would be indicated if the carcinoma had not metastasized. However the prognosis is poor.