Development of canine benign prostatic hyperplasia with age.

The prevalence and growth of benign prostatic hyperplasia (BPH) in beagles as a function of age were studied. The normal prostate gland was 12 +/- 3 gm in beagles 2.1-3.0 years of age; this weight remained unchanged unless BPH developed. Histologic evidence of BPH developed at an early age with a prevalence of 16% of the dogs by the age 2 years. Fifty percent of the dogs had BPH, determined histopathologically by age 4.1-5.0 years. The average weight of the prostate gland remained constant until after age 8 years. With age, the pathologic features of BPH changed from glandular to the complex form, with no increase in prostate weight until after 8 years. Reinitiation of growth occurred and prostate weight increased to greater than 36 gm in eight of 185 beagles older than age 8 years.