Any problem that interferes with the passage of intestinal contents through the GI tract results in a blocked bowel. Dogs experience bowel obstruction more often than cats because they love to chew. This eventually leads them to swallowing non-digestible objects like sticks and stones.
When the blockage is up high in the intestinal tract, projectile vomiting will occur, and your pet may not be interested in eating. A blockage lower in the system will also cause vomiting, but it will be less frequent, dark brown, and smell like feces, and the abdomen will swell.
An intestinal obstruction can be partial or complete. Partial obstructions cause intermittent vomiting and/or diarrhea, which tend to occur over several weeks. Complete obstructions produce sudden abdominal pain and vomiting that continues without relief. When blockage is in the upper small bowel, the vomiting may be projectile. Blockages in the lower GI tract cause abdominal distension and the vomiting of brown, fecal smelling material. Dogs with complete obstruction pass no stool or gas.
The most common cause is a gastrointestinal foreign body. The second most common cause is intussusception, a situation in which the bowel telescopes in upon itself, like a sock pulled inside out. Most cases of intussusception occur at the cecum, where the small bowel joins the colon. As the small bowel inverts into the cecum and colon, the lead point travels a considerable distance, dragging the small intestine after it. Intussusceptions generally occur in puppies and young dogs.
Other causes of intestinal obstruction are tumors and strictures, adhesions following abdominal surgery, and navel and groin hernias that trap loops of bowel in the hernia sac. In young puppies, heavy infestations of roundworms may obstruct the bowel.
Intestinal strangulation occurs when the obstruction interferes with the blood supply to the bowel. Within hours the bowel becomes gangrenous. the dog's condition deteriorates rapidly.
The diagnosis of intestinal obstruction is made by abdominal X-rays or ultrasound showing distended, gas-filled loops of bowel.
Obstructions require immediate veterinary attention. Surgical exploration and relief of the blockage is necessary. Gangrenous bowel is resected back to viable bowel, and intestinal continuity is restored with end-to-end suturing of the bowel.
There is no prevention for this condition.
Please contact your veterinarian if you suspect your pet may have this condition.
Show Sources & Contributors +
Dog Owners Home Veterinary Handbook
Publisher: Wiley Publishing, 2007
Authors: Debra M. Eldredge, Liisa D. Carlson, Delbert G. Carlson, James M. Giffen MD
The First Aid Companion for Dogs And Cats
Publisher: Rodale Inc, 2001
Authors: Amy D. Shojai, Shane Bateman DVM