It is interesting to note that the aging dog (like his master) is also prone to prostatic enlargement, but (unlike his master) does not often develop retention of urine. However, due to the bulging upwards of the enlarged prostate the dogs rectum is compressed. This engenders a feeling of continuous fullness in the rectum and induces straining. The prostates of eunuchs are small and underdeveloped, and enlargement of the prostate is unknown.
Benign prostatic hyperplasia (BPH) is one of the most common diseases to affect men beyond the middle age. The prevalence goes up with age, and thus the total number of patients is increasing as a result of aging population. A majority of these people suffer gradual progression of symptoms and the concomitant discomfort, and require either medical or surgical treatment. The growth and development of the prostate is under the influence of male hormone testosterone.
Rather surprisingly, there is no close correlation between the size of the prostate and the extent of outflow obstruction. However, the larger the prostate, the greater is the risk of BPH complications such as acute urinary retention and the need for surgery.