Prince, a 7 year-old unneutered German Shepherd, was not feeling his best. He’d been having trouble urinating more than small amounts at a time for a couple of days. He’d had an accident in the house, which was very unlike him. And sometimes he leaked a little urine while lying down. On physical exam, Prince’s bladder felt much distended. On his x-rays, his bladder was very full, and his prostate gland was visibly enlarged.
What could this mean for Prince? And what could we do about it?
NORMAL PROSTATE GLAND
The prostate gland is located behind the urinary bladder in the dog, encircling the urethra (the tube that carries urine out of the bladder). It should be smooth and symmetrical. Its location varies with age and size, but it can usually be felt by the veterinarian during a rectal exam. The prostate produces fluid that serves as transport and support for sperm, and its’ secretions have some antibacterial properties.
When the prostate gland becomes enlarged, there are a few common scenarios that can be the cause.
BENIGN PROSTATIC HYPERPLASIA
Benign prostatic hyperplasia (BPH) happens regularly to intact dogs, and can begin as young as 2.5 years of age. I have personally seen more cases of this in the past couple of years, as more dog owners are waiting until later to neuter or forgoing neutering altogether due to potential health benefits of keep them intact longer. Increased blood supply with hyperplasia can lead to clinical signs of blood in the urine and/or on the prepuce. The enlarged prostate may put pressure on the rectum, causing difficulty with having a bowel movement. Other than these clinical signs, affected dogs are usually normal, alert, and active. The prostate is symmetrically enlarged and is not painful. Abdominal x-rays confirm mild to moderate prostate enlargement, which may move the rectum and push the bladder forward in the abdomen. Definitive diagnosis is only possible by biopsy; however, a biopsy is not needed to start therapy if the clinical signs are typical.
Treatment is only required if signs are present. If asymptomatic, the owner can watch for development of typical clinical signs. The most effective treatment is neutering, which results in a 50% reduction in prostate size within 3 weeks, as testosterone levels decrease.
ACUTE AND CHRONIC PROSTATITIS AND ABSCESSATION
Prostatitis and abscessation are inflammatory diseases of the prostate gland, usually due to bacterial infection. Abscesses develop when the infection is severe. Blood cells and bacteria in the urine are common in prostatic infections. If the urinalysis indicates infection, a urine culture and sensitivity should be performed. Abdominal pain is present in 75% of cases and can be localized to the prostate gland. The dog may walk stiffly and appear uncomfortable. The prostate is usually not painful, but may vary in symmetry and consistency.
X-rays may be normal or show a loss of detail at the margins of the prostate gland in acute prostatitis. A definitive diagnosis of acute prostatitis is rarely made, since prostatic biopsy and tissue culture are usually not performed. Fine needle aspiration or exploratory surgery should confirm the diagnosis of abscessation since the current treatment of choice is surgical drainage. At surgery, the abscess contents are collected for aerobic and anaerobic culture and a tissue section is obtained for microscopic examination.
Antibiotics are continued for at least 6 weeks. Neutering may be beneficial for resolution of chronic bacterial prostatitis. Relapses are common. Surgical drainage is currently the treatment of choice for prostatic abscess. Complications are common with all methods. Prostatic abscesses are difficult and expensive to treat. Urinalysis and urine culture is evaluated monthly for several months after initial therapy is discontinued.
Aging dogs can develop prostate cancer, most commonly adenocarcinoma and transitional cell carcinoma. This can occur in both intact and neutered dogs. Prostatic neoplasia is the most common prostatic disease diagnosed in dogs neutered prior to the onset of prostatic disease.
Signs in affected dogs include difficulty defecating and/or urinating, bloody penile discharge, rear limb weakness, stiffness, and/or pain, and chronic weight loss and anorexia. In most cases, the gland will be enlarged and asymmetric with increased firmness. It may be painful on palpation. Bloodwork is usually normal. Evidence of kidney stress may be present due to obstruction of the ureters or urethral obstruction. Asymmetrical, irregular prostate enlargement may be seen on x-rays. Chest x-rays are indicated to check for spread to the lungs. A biopsy or aspirate is necessary to determine the presence and type of cancer.
Now, back to Prince.
Initially, we were concerned about prostate cancer due to the size of his prostate and the fact that his urethra was very nearly completely obstructed. His prostate was enlarged, but symmetrical and non-painful. There was no mineralization or other troubling changes in his prostate on ultrasound.
These findings and the fact that Prince was intact, led us to hope that benign prostatic hypertrophy was the culprit. We scheduled his neuter surgery for the next day. He was prescribed an antibiotic, an anti-inflammatory, and his owners began giving him Saw Palmetto with his meals.