Hernias are defects or weaknesses in the muscles that keep the organs such as the intestines, bladder and stomach in the abdomen. The rectum and anus are held in place by five muscles, that are altogether called the pelvic diaphragm. Perineal hernias develop on one or both sides of the anus due to weakness in the muscles that constitute the pelvic diaphragm. Seen in both dogs and cats, perineal hernias describe the displacement of pelvic and abdominal organs (rectum, prostate, bladder or fat) into the perineal region alongside the anus.
Hernias are defects or weaknesses in the muscles that keep organs, such as the intestines, bladder and stomach in the abdomen. The rectum and anus are held in place by five muscles, which altogether are called the pelvic diaphragm. Perineal hernias develop on one or both sides of the anus, due to weakness in the muscles that constitute the pelvic diaphragm. Seen in both dogs and cats, perineal hernias describe the displacement of pelvic and abdominal organs (rectum, prostate, bladder or fat) into the perineal region alongside the anus.
Weakness of the supporting muscles that results in perineal hernia occurs almost exclusively in older and un-neutered male dogs. Unlike in other areas of the body, hormones, like testosterone, are presumed to weaken the muscles and tissues that constitute the pelvic diaphragm. An enlarged prostate gland, more common in un-neutered middle-aged to older male dogs and cats, may cause straining to urinate or defecate (bowel movement), putting additional stress on the pelvic diaphragm. For this reason, veterinarians recommend neutering at the time of hernia repair.
Whenever your pet is showing signs of a health issue, your first step is to contact your primary care veterinarian. If it is indicated that your pet may suffer from a perineal hernia or another serious condition, a veterinary specialist is available at an ExpertVet certified hospital.
Signs and Symptoms
Perineal hernias result in swelling on either side of the anus and can occur on one or both sides. The most common sign associated with perineal hernias in dogs is straining to defecate. This occurs because the rectum balloons into the hernia, and trapped fecal material cannot pass out of the body easily. Constipation and swelling around the anal region are also noticed. Because defecation may become difficult, your pet may experience loss of appetite. Straining to urinate may be seen if the bladder becomes trapped in the hernia. If the small intestine slips into the hernial sac and becomes entrapped, vomiting and depression may be seen. Because perineal hernias can result in organ entrapment of the bladder or intestines, they can become a serious condition that requires emergency surgery to correct.
The diagnosis of a perineal hernia is made during an examination by your veterinarian. External palpation and a rectal examination will generally confirm the suspected hernia. Additional diagnostic procedures may include X-rays and an ultrasound of the abdomen and hernia to make sure that the bladder is not displaced into the hernial sac.
Lab work, like a complete blood count, chemistry profile, and urine testing are performed before surgery to allow your veterinarian to determine if there are other medical conditions present and to choose the best anesthetic protocol for your companion.
Treatment requires surgery to repair and stabilize the weakened pelvic diaphragm musculature and neutering (castration) to remove the hormonal influence testosterone has on muscle weakness and prostate enlargement. Prior to surgery, the surgeon will determine if the bladder is trapped within the hernial sac. If this is the case, a catheter is placed into the urethra and bladder to relieve the build up of urine and to allow the bladder to be replaced into the abdomen.
If there is no organ entrapment, surgical correction can be performed at a scheduled time, as opposed to on an emergency basis. Surgery involves replacement of the hernia contents back into the abdomen and reconstruction of the muscles of the pelvic diaphragm using suture. This reconstruction generally uses the surrounding musculature, but may include use of a synthetic mesh (SIS or polypropylene) in some cases. In some patients with bladder retroflexion and severe herniation, the surgeon may also choose to operate inside the abdomen to permanently affix the bladder and the colon to the interior of the abdominal wall (cystopexy and colopexy). This can help to prevent recurrent displacement of these organs into the repaired hernia.
Complications can occur with any surgical procedure in the perineal area. Infection is uncommon with careful attention to sterile techniques and use of broad spectrum antibiotics during and after surgery. Other complications may include fecal incontinence, rectal prolapse (where the stretched rectal lining everts through the anal opening), and recurrence of the hernia. In cases where the hernia is only on one side, the opposite side may also weaken and develop a hernia in the future. The recurrence rate after surgical repair is about 10 to 15%.
After surgery, your pet will receive pain medications and be placed on a special diet and/or stool softeners to decrease straining and make defecation easier. It is important to not allow any strenuous activity for at least 30 days to prevent undue stress on the repaired muscles in the hernia. Call your veterinarian immediately if your pet has excessive swelling and redness around the incision area, if there is drainage from the incision or develops a fever, as all of these could be signs of infection and should be addressed immediately.