What is bowel incontinence?
Bowel incontinence refers to the loss of the ability to control bowel movements.
Bowel incontinence can present 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 are 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 refers to 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 refers to the inability of the anal sphincter (the muscle that closes the anal opening) to remain in a closed position. When the anal sphincter does not close properly, feces can leak out. There are two possible causes of sphincter incontinence. Any lesion that disrupts the anal sphincter, such as an anal wound or mass, can interfere with its function. Additionally, damage to the nerves that control the anal sphincter (which stem from the spinal cord and travel to the sphincter) can interfere with its ability to function normally.
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, and/or changes in how the tail is carried.
In cases of reservoir incontinence, the dog is typically aware of the defecation but unable to control it. You may notice that your pet is defecating in strange places, like right near the door (which suggests that he/she is unable to hold feces until reaching an appropriate location). The feces of pets with reservoir incontinence is often 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. The anal area will be closely inspected for evidence of masses or inflammation and a rectal palpation will be performed 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 (e.g., how the nerve supply is funtioning within these areas).
If your veterinarian suspects a neurologic cause for your pet’s bowel incontinence, additional imaging may be required. Radiographs of the spine are often the first step, in order to look for evidence of vertebral abnormalities and/or intervertebral disk disease. If spinal radiographs are normal, advanced imaging (such as CT scan or MRI) may be recommended.
"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."
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 workup may include abdominal radiographs, abdominal ultrasound, endoscopy, or surgical biopsies of the intestines.
How is bowel incontinence treated?
The treatment of bowel incontinence depends upon the underlying cause. There is no medication that specifically addresses bowel incontinence; therefore, the underlying cause must be identified and addressed.
"The treatment of bowel incontinence depends upon the underlying cause."
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. 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.