Rectal Prolapse in Dogs

Rectal prolapse in dogs can occur at any age and can be congenital or develop later in life.  Though this condition can occur in both males and females, the female is put more at risk during the birthing process.  Younger dogs are more often affected as there are several diseases that can cause straining in puppies which may cause the protrusion of the rectum through the anus.

Rectal prolapse is defined as the protrusion or pushing out of the inner layers of the rectum through the anus.  This often occurs after straining to defecate, urinate or give birth.

Rectal prolapse symptoms are quite simple: 

• Visual observation and noting of a mass protruding from the anus; this mass will appear similar to a “sausage or dough-nut” and it will be reddened
• There may be pain in the area, similar to the discomfort experienced by humans with regard to hemorrhoids, though dogs don’t get hemorrhoids
• You may notice your pet straining to produce a bowel movement, urinate or straining during a difficult birth. Any protruding tissue can then cause an urge to continue straining.

Types

There are two types of rectal prolapse per se but there are several other rectal disorders in which rectal prolapse is a sign.  The two true types of rectal prolapse are:

• Incomplete, in which only the innermost rectal layer is actually protruding
• Complete, in which all of the layers of the rectum are protruding.

There are several other disorders of the rectum in which rectal prolapse may occur; they are:

Anal Sac Disease

This disorder involves the anal sacs which are positioned on either side of the anus.  This is the most common disease found in the anal area of a dog.  They become clogged, infected, abscessed or even cancerous, making defecation difficult.  The other signs that you might see in this case would be related to pain or discomfort while sitting, scooting the buttocks on the ground, licking or biting at the anal area.

Perianal Fistula

The most prominent signs are chronic, foul-smelling wounds in the tissues that encompass the anus (the cause is unknown), most often found in German Shepherds and less frequently in Setters and Retrievers.

Perineal Hernia

This is a hernia that happens near the anus most often in males, 6 to 8 years old, who have not been neutered.  Typical breeds affected are Boston Terriers, Welsh Corgis, Boxers, Collies, Kelpies, Dachshunds, Old English Sheepdogs and Pekingese.

Rectal and Anorectal Narrowing

These are narrowing of the rectal area as a result of scar tissue from injury from foreign objects or trauma or they may be a complication of inflammation.  This type generally has both rectal and anal involvement.

Rectal tears, as well as anal tears, can occur when a dog swallows a foreign object that is sharp, like a bone, needle or other rough material. They can also result from a bite or injury.  The tear may involve only the surface layers of the rectum (called a partial tear) or may it may puncture through all the rectal layers (called a complete tear). Swelling or edema may also be seen if the condition is long standing. Tears can result in narrowing of the anorectal region as they heal and form scars.

Rectal Tumors

Rectal tumours can be benign or malignant. If the tumour is malignant and/or interfering with the dog's day to day life, surgical removal is the primary treatment option but may not always be effective if the tumor has spread beyond the rectum before the signs were noted. The signs of this disorder include the straining and painful defecation noted above as well as bright red blood in the feces and diarrhea.

In addition, rectal polyps are basically growths that appear in the rectal area.  This is not a frequent occurrence in dogs and they’re typically benign when they do appear.  The bad news is that, generally speaking, the larger the polyp in size, the increased chance it will  be a malignancy.

The main cause of rectal prolapse in dogs, whether it’s a primary or a secondary condition, is straining to either defecate or urinate in both sexes and difficult birthing in females.  There are some conditions and diseases which can contribute to the prolapse of the rectum, regardless of age or sex including:

• Straining to defecate or urinate at any age
• Difficulty in giving birth
• Severe diarrhea (often associated with chronic parasitic infections) especially in puppies but can occur at any age
• Constipation
• Straining to urinate because of urinary infection or other urinary disease
• Obesity in dogs cause poor muscle tone and contributes to the failure of the anal sac to be fully emptied during defecation
• When the contents of the gland are not adequately emptied regularly, the gland becomes a target of bacterial infection and inflammation
• Prostate disease
• Pelvic muscle weakness
• Swallowing of foreign objects, especially sharp or rough things, causing grazes and lacerations
• Cancer

The primary diagnostic tool for rectal prolapse in dogs is the physical examination.  This examination will provide a great deal of information to your veterinarian as to which organs and tissues are actually involved. This examination may involve the use of a probe inserted next to the prolapsed tissue to determine its identity.  It is important for the veterinarian to know if the prolapsed tissue is intestinal or rectal so that appropriate treatment options can be explored.  If the protruding tissue is intestinal, prompt surgery will be required to put it back where it belongs.

Treatment of rectal prolapse in dogs will depend upon the tissue involved and the reason it is prolapsed.  If anal sac disease is also present, the anal sacs will need to be expressed to empty them.  This may require manual expression by the veterinary caregiver using his finger.  

When possible, the tissue will be gently cleaned and repositioned. A suture may be temporarily placed to hold things in position. In more extreme cases, surgery may be required. A decision for surgical intervention must be carefully considered based on the cause and degree of prolapse.  There are possible complications with any anaesthetic and surgery and your veterinarian will need to consider if the prolapsed condition warrants the risks of the possible complications that are associated with this surgical repair.  

Regardless of the treatment option recommended, the prolapsed tissue will need to be returned to its normal position and location by some means.  In the event that the prolapse is caused by a tumor, that, of course, will need to be surgically removed to prevent possible cancerous metastasis.

The prognosis for most disorders of the rectum is good but may require closer observation and dietary changes over the rest of the pet’s life.  You will need to monitor your pet frequently and in your regular observation of your dog, watch for prolapses, straining to defecate or urinate, diarrhea episodes, pain with defecation, urination, sitting, and walking. Note any changes in urinary or bowel habits as obstructions in either of these systems can quickly become an emergent situation. Your veterinarian will likely want to follow up after treatment periodically to ensure the prolapse doesn’t return or, in the event it does return, that it can be treated expeditiously to avoid permanent damage to your pet.