What is bowel incontinence?
Bowel incontinence is the loss of the ability to control bowel movements. Bowel incontinence can appear in a number of different ways. In some cases, dogs with bowel incontinence may drop small amounts of feces without any awareness that they are doing so. In other cases, pets may be aware of their bowel movements, but unable to control them.
What causes bowel incontinence?
Causes of bowel incontinence can be divided into two broad categories: reservoir incontinence and sphincter incontinence.
Reservoir incontinence results from any disease of the rectum (the last part of the large intestine that leads out of the body) that prevents stool from being held or stored in a normal manner. This can occur in cases of diarrhea, inflammatory bowel disease, cancer, or any other disease that affects the intestines. In a dog with reservoir incontinence, the rectum cannot store a normal volume of stool, which results in the pet being unable to control the urge to defecate.
Sphincter incontinence occurs when the anal sphincter (the muscle that closes the anal opening) is unable to remain in a closed position. When the anal sphincter does not close properly, feces can leak out. This inability to close may be caused by a lesion, such as an anal wound or mass, that disrupts the anal sphincter and interferes with its function. Or it may be caused by damage to the nerves that control the anal sphincter (which come from the spinal cord and travel to the sphincter.
What are the clinical signs of bowel incontinence?
The clinical signs of bowel incontinence vary, depending on the severity of the disease and its underlying cause.
Dogs with sphincter incontinence typically leak small volumes of stool without awareness. You may notice occasional fecal balls in your pet’s bed or deposited around the home. Dogs may also dribble small amounts of feces when barking or excited. If the sphincter incontinence is caused by anal sphincter damage or disease, you may notice redness, inflammation, or drainage from your dog’s rectum. Additionally, your pet may lick at the rectum more than usual. If sphincter incontinence is caused by nerve damage, you may observe that your pet has trouble walking, urinary incontinence (dribbling or puddling urine), and/or changes in how they carry their tail.
In cases of reservoir incontinence, the dog is typically aware of the defecation but unable to control it. You may notice that your pet defecates in strange places, like near the door (which suggests that they are unable to hold feces until reaching an appropriate location). Pets with reservoir incontinence often have feces that are soft and there may be blood and/or mucus present.
How is bowel incontinence diagnosed?
Your veterinarian will begin by performing a thorough physical exam. They will closely inspect the anal area for evidence of masses or inflammation, and they will perform a rectal palpation to rule out internal rectal lesions. Your veterinarian will also perform a thorough neurologic exam, looking for changes to the innervation of the hindlimbs, anal sphincter, and tail (i.e., how the nerve supply is functioning within these areas).
"If your veterinarian suspects a neurologic cause for your pet’s bowel incontinence, additional imaging may be required."
If your veterinarian suspects a neurologic cause for your pet’s bowel incontinence, additional imaging may be required. X-rays (radiographs) of the spine are often the first step, to look for evidence of vertebral abnormalities and/or intervertebral disk disease. If spinal X-rays are normal, advanced imaging may be recommended, such as CT scan or MRI.
If your veterinarian suspects intestinal disease as the cause of your pet’s bowel incontinence, the first diagnosis tests typically include a fecal parasite examination and blood tests (including a complete blood cell count, serum biochemistry, and perhaps additional specialized gastrointestinal blood tests). Further workups may include abdominal X-rays, abdominal ultrasound, endoscopy, or surgical biopsies of the intestines.
How is bowel incontinence treated?
Bowel incontinence treatment depends on the underlying cause. There is no medication that specifically addresses bowel incontinence, so the underlying cause must be identified and addressed.
In a dog with reservoir incontinence, treatment will be centered on diagnosing and treating the underlying bowel disease. Anti-diarrheal and anti-inflammatory medications may be used, either as a sole therapy or in addition to other, more specialized treatments.
In a dog with sphincter incontinence that is caused by a lesion of the anus (such as a wound or mass), surgical treatment may be necessary. This surgery may be performed by your family veterinarian or may require referral to a veterinary surgical specialist.
Sphincter incontinence caused by nerve lesions may be challenging to treat. In some cases, surgery may be recommended to address a herniated disk or other neurologic lesion. In other cases, however, there is no definitive treatment and instead the focus shifts to management. Feeding a low-fiber diet may decrease the quantity of feces that is produced, or a high fiber diet may be recommended to make cleaning up the stool easier. Confining your pet to an area of the home that is easy to clean may help minimize the stress on the family that can be associated with fecal incontinence.
