How an Enlarged Prostate Affects Dogs
Benign prostatic hyperplasia (BPH) usually causes no symptoms in domestic dogs. Even when symptoms do occur, the dog usually is otherwise in good health and is not in a great deal of discomfort or distress. As the prostate gland enlarges in a sexually intact aging male, it eventually may physically press on the rectum (the end of the large intestine) and the urethra (the passageway for urine from the bladder to the outside). This can cause a number of unpleasant symptoms due to mechanical interference with the dog’s normal bodily functions and stimulation of nerves that normally are not subject to that pressure.
Symptoms of Benign Prostatic Hyperplasia
As mentioned above, most dogs with BPH show no noticeable signs of their condition. When symptoms do become evident to owners, they typically include one or more of the following:
- Blood in the urine (hematuria)
- Blood in the ejaculate
- Bloody, thick discharge from the urethra (seen at the tip of the penis; not necessarily associated with urination)
- Straining or obvious effort to defecate (tenesmus)
- Difficulty urinating (dysuria)
- Abnormally formed, flat, ribbon-like stools
- Infertility or subfertility
- Pain (+/-)
- Symmetrically enlarged prostate gland (detected by rectal palpation)
- Pain (if there is accompanying prostatic abscesses, infection or cancer)
Dogs at Increased Risk
Sexually intact, aging males have a greatly increased risk of developing benign prostatic hyperplasia. Because BPH is largely hormone-dependent, it is almost always seen only in unneutered dogs. BPH can be seen in young adult intact males as early as 1 to 2 years of age. However, the average age of onset is closer to 8 years, depending on the size and breed of the dog. Large and giant breeds have a shorter expected life span than do smaller dogs. As a result, BPH is often detected at a younger age in intact males of the larger breeds. According to experts, roughly 50% of intact male dogs will be affected by BPH by the time they reach 5 years of age, 60% will be affected by 6 years of age, and 95% will be affected by the time they are 9 years old.