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

262 •DOG OWNER’S HOME VETERINARY HANDBOOK
Other conditions that predispose a dog to ulcers include all forms of liver
disease, kidney failure, extreme stress (from severe illness or major surgery),
chronic gastritis (particularly the eosinophilic type), and shock.
Mast cell tumors of the skin (see page 533) can cause ulcers. This is
because these tumors produce and release histamine, which is a powerful stimulant
to acid secretion. In fact, ulcers occur in up to 80 percent of dogs with
mast cell tumors.
The principal sign of an ulcer is sporadic or chronic vomiting. Dogs may
also lose weight and be anemic. In dogs with nonspecific signs, such as
chronic vomiting, the diagnosis is made by gastroscopy.
Occasionally the vomitus contains old blood (which looks like coffee
grounds) or fresh blood and blood clots, although the bleeding in many ulcers
is microscopic. With rapid bleeding the dog goes into shock and passes black,
tarry stools. Stomach and duodenal ulcers can rupture into the abdomen,
causing peritonitis.
Treatment: Perforated ulcers require emergency surgery. Dogs with gastrointestinal
bleeding should be hospitalized for observation and further tests. Severe
anemia is treated with blood transfusions. It is important to identify and eliminate
predisposing causes. Discontinue all ulcer-producing medications.
Ulcer drugs used in people are effective in dogs. They include the histamine
blockers Tagamet (cimetidine), Pepcid (famotidine), and Zantac (ranitidine);
the mucosal protectants Carafate (sucralfate) and Cytotec
(misoprostol); Prilosec (omeprazole); and antacids such as Mylanta, Maalox,
and Amphogel. These drugs are best taken in combination (an antacid along
with a histamine blocker), several times a day. A veterinarian should determine
the most effective drug combination and schedule. Treatment is continued
for at least three to four weeks. A follow-up gastroscopy is advisable to
ensure that healing is complete.
GASTRIC OUTFLOW OBSTRUCTION
At the outlet of the stomach is the pyloric canal. Scarring and contraction of
the pyloric canal prevents the stomach from emptying. Stomach and duodenal
ulcers close to the pyloric canal are the most common causes of inflammation
and scarring. Other causes of scarring and contraction include
hypertrophic and eosinophilic gastritis (see Chronic Gastritis, page 268), and
gastric tumors. Foreign bodies and bezoars are other causes of gastric outflow
obstruction (see Gastrointestinal Foreign Bodies, page 276).
Gastric outflow obstruction can be partial or complete. Dogs with partial
obstruction vomit intermittently, often 12 to 16 hours after eating. The vomitus
usually contains undigested food and, occasionally, blood. When obstruction
is complete, vomiting occurs immediately after eating and is often