Fecal incontinence occurs when a loss of control of the lower bowel and rectum allows feces or stool to be passed at inappropriate times or places. Fecal incontinence may be neurogenic in origin associated with the failure of nervous sensation. In these cases, the animal does not realize that it is defecating and does not assume a normal posture for defecation. In contrast, urge incontinence may occur with uncontrolled strong urges to defecate. In these cases, the animal acutely needs to defecate and is aware of that need.
Diseases of the nerves in the lower spine, and of the rectum and anus can all result in fecal incontinence. Masses or tumors in the wall of the rectum or in the pelvic canal can also lead to excessive straining. Urge incontinence can result from inflammation to the lower colon, which is called colitis. Some older animals develop incontinence from a decline in mental status, or senility, which leads them to become less attentive to many aspects of daily life.
Examination of the rectum and anus with a gloved finger is usually done to check the strength of the rectal sphincter and the presence or absence of masses or other diseases. Routine laboratory tests and X-rays and abdominal ultrasounds may be recommended to screen for pelvic spinal or other diseases.
If the primary cause of the incontinence can be identified, such as a slipped disc in the spine or severe degenerative joint disease in the lower back and pelvis, your veterinarian may recommend surgery. These types of surgery can be complex and difficult, so your pet may be referred to a veterinary specialist. Animals with fecal incontinence from colitis generally respond well to changes in diet and anti-inflammatory drugs. Animals with fecal incontinence from cognitive dysfunction may be treated with drugs that stimulate mental activity, though these treatments do not produce a reliable positive response in all animals. No effective treatment is available for some forms of neurogenic incontinence.
Prognosis varies widely, depending on the cause of the fecal incontinence. Animals with urge incontinence from colitis have a good prognosis once the colitis is controlled. Prognosis for incontinence resulting from cognitive decline or neurological disease is more variable and generally poorer. Prognosis for dogs with tumors and osteoarthritis of the lower back depends on the success of the surgery.
Dr. Karsten Fostvedt is a veterinarian at St. Francis Pet Clinic in Ketchum.