Sexually intact aging male dogs commonly develop benign prostatic hyperplasia, also called BPH or prostatomegaly, which is a non-painful, non-cancerous, hormone-dependent condition involving an enlarged prostate gland. (Prostatic cancer, infection, abscesses and cysts can also cause enlarged prostates.) The prostate surrounds the neck of the bladder (where urine exits) and the beginning of the urethra (the tube that carries urine from the bladder to the outside world). It contributes to the fluid part of semen. Many dogs never show signs of BPH. However, as a dog’s prostate gets bigger, it can press on the rectum, which is the end of the colon or large intestine, causing constipation, difficulty defecating and flat, ribbon-like stools. An enlarged prostate can also put pressure on the urethra. This can cause discomfort, pain, bloody penile discharge and an artificial sense of urgency to urinate. Owners should consult a veterinarian to confirm a diagnosis of BPH and work out a management plan.