TL;DR: Fecal incontinence in dogs is the physical inability to control bowel movements and usually requires a veterinary exam within 24 to 48 hours, unless accompanied by sudden weakness or severe pain.
What is fecal incontinence in dogs and what causes it?
When a dog loses bowel control while awake, it is medically referred to as fecal incontinence. Unlike a house-training lapse, this occurs when a dog is physically unable to control the muscles of the anal sphincter or is unaware that they are defecating. It can result from nerve damage, spinal cord issues, or problems within the gastrointestinal tract itself.
Is my dog's loss of bowel control a medical emergency?
- The urgency level for sudden loss of bowel control is Medium, meaning the dog should be seen by a veterinarian within 24 to 48 hours.
- Seek emergency care immediately if the incontinence is accompanied by sudden hind-limb weakness, an inability to stand, or signs of extreme pain.
Why should I take a photo of the stool to help with veterinary triage?
- A photo allows the veterinarian to see the consistency and color of the stool.
- Visual evidence helps determine if the issue is a digestive upset, such as severe diarrhea, or a neurological failure where the dog unknowingly "dropped" normal stool.
- Capturing how the stool was deposited provides context on whether the dog was aware of the event.
Clinical Context (Merck Veterinary Manual)
Loss of bowel control while awake can be attributed to several underlying causes. Compression of the colon or rectum may occur due to a narrowed pelvic inlet from improperly healed pelvic fractures, enlarged sublumbar lymph nodes, or an enlarged prostate gland. Colonic stricture resulting from trauma or neoplasia should also be considered. In some cases, chronic constipation or obstipation can lead to megacolon, possibly due to neuromuscular lesions of the colon. Other diseases affecting neuromuscular control of the colon and rectum include hypothyroidism, dysautonomia, and spinal cord lesions (e.g., Manx sacral spinal cord deformity) or pelvic nerve damage. Furthermore, electrolyte imbalances like hypokalemia and hypercalcemia, as well as certain medications (e.g., opioids, diuretics, antihistamines, anticholinergic agents, sucralfate, aluminum hydroxide, potassium bromide, and calcium channel-blocking agents), can contribute to constipation and subsequent loss of bowel control. Severe diarrhea and tenesmus, often seen in young animals with enteritis or endoparasitism, can also lead to rectal prolapse, further complicating bowel control. A thorough physical and neurological examination should be performed to determine the presence of perineal hernia, foreign material, pain or masses.
Chapter: Gastroenterology
Source: The Merck Veterinary Manual, 11th Edition (Page 381)