Dog Owner's Home Veterinary Handbook.pdf - Mr. Walnuts

The esophagus of the dog is larger than the outlet of his stomach. Thus,
dogs may swallow objects that are too large to pass out of the stomach. Gastric
foreign bodies are therefore associated with chronic gastritis and episodes of
gastric outflow obstruction.
If an object makes it into the small intestine, it may pass through the entire
GI tract without causing problems. Those that do cause an obstruction usually
do so at the ileocecal valve or in the colon and rectum. Foreign bodies in the
rectum cause anorectal obstructions. Sharp objects such as pins, splinters, and
bone chips can lodge anywhere in the GI tract and obstruct or perforate the
bowel, causing intestinal obstruction or peritonitis.
Unless it also causes indigestion, a swallowed foreign body will go unnoticed
until it produces symptoms. Many foreign bodies can be seen on X-rays
of the abdomen if they are radio-opaque. A contrast study may be needed to
identify foreign bodies that are not visible on X-rays.
Treatment: Foreign bodies that produce symptoms should be removed.
This usually involves abdominal surgery. Gastric foreign bodies can sometimes
be removed through an endoscope.
INTESTINAL OBSTRUCTION
THE DIGESTIVE SYSTEM • 277
Any problem that interferes with the passage of intestinal contents through
the GI tract results in a blocked bowel. 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.
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 the 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.
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 (see Peritonitis, page 279).