All intact, male dogs will experience benign prostatic hyperplasia and hypertrophy, usually by around 6 years old. Although these dogs will be predisposed to prostatic infections, only a small subset will actually develop infections or show clinical signs of discomfort or subfertility. Neutered male dogs have a higher incidence of neoplasia associated with the prostate. Updated diagnostic tests, including canine prostate-specific arginine esterase, are discussed. Castration is compared with medical treatment options. Updated treatment recommendations include reducing antibiotic exposure to 4 weeks for bacterial infections and use of nonsteroidal antiinflammatory drugs for neoplastic disease.