Perineal Hernia

What is it?

The perineum is the area between the anus and the scrotum or vulva, and its muscles support the pelvic organs. When those muscles weaken or tear, the bladder, intestines, or fat can push through and bulge beside the anus. Most hernias come from gradual muscle weakening rather than injury. Hormones likely play a role, since unneutered males are most often affected; nerve damage and repeated straining can also contribute. Female dogs and cats rarely get them.

What signs should I watch for?

Look for a soft swelling on one or both sides of the anus that can usually be pressed back in. Affected dogs often strain repeatedly to pass stool and may become constipated. If the bladder is involved, a dog may strain to urinate, leak urine, or be unable to urinate. Lethargy and poor appetite can mean intestine or bladder is trapped, which can be life-threatening.

How is it diagnosed and treated?

Your veterinarian can often feel the hernia on a rectal exam. Blood and urine tests, X-rays, or ultrasound show which organs are involved and check for problems such as prostate disease. A trapped bladder needs emergency catheterization and fluids. Otherwise, stool softeners and diet help in the short term, and surgery to repair the muscles is the most successful treatment, sometimes with a mesh implant. Neutering at the same time is recommended, and a second surgery may be needed if both sides are affected.

Can it be prevented, and what's the outlook?

• Neutering and treating any cause of straining greatly reduce the risk of recurrence; unneutered dogs are almost three times more likely to get another hernia.
• With good surgical repair, the outlook is very good.
• Referral to a board-certified surgeon is often recommended.