Effects of oral administration of chlormadinone acetate on canine prostatic hypertrophy

Seven of the 25 dogs (4 to 15 years old) with benign prostatic hypertrophy (BPH) at the teaching hospital of Nippon Veterinary and Animal Science University from 1989 through 1990 were treated orally with chlormadinone acetate (CMA), a synthetic anti-androgen, 2 mg/kg/day, twice a day for 3 or 4 weeks. Prostatic size was measured by radiography and ultrasonography before and after CMA treatment, and prostatic volume was calculated from the images. Semen quality was examined in 3 of the dogs with BPH. Peripheral blood simples were collected and plasma levels of LH, 4-androstenedione, 5α-dihydrotestosterone, testosterone and estradiol-17β were measured. Clinical signs disappeared within 10 days after the start of CMA treatment. The mean (±S.E.) prostatic volume 3 or 4 weeks after treatment decreased to 39±4% of the pretreatment volume. The mean level of plasma testosterone in the dogs with BPH before treatment was significantly lower than that in the normal dogs (P