Telemedicine: Is endoscopy needed when dog presents with vomiting, anorexia? - DVM
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Telemedicine: Is endoscopy needed when dog presents with vomiting, anorexia?


DVM360 MAGAZINE


Acute or chronic vomiting with or without hematemesis is the most common clinical sign associated with duodenal ulcer or erosion formation. "Not all dogs with duodenal ulcers vomit, and not all dogs that vomit blood have gastric and/or duodenal ulcers." Other clinical signs observed include anorexia, abdominal pain, melena, anemia, edema (from hypoproteinemia related to active alimentary hemorrhage) and/or septicemia (from existing perforation). The other signs may be more related to the underlying cause (such as liver disease, pancreatic disease, renal disease, neurologic disease). Perforation of the duodenum often results in the sudden onset of severe generalized weakness, severe abdominal pain, fever, shock, abdominal distention and death caused by peritonitis.

The diagnosis of duodenal ulcers or erosions requires either direct visualization with endoscopy or possibly indirect documentation with an upper GI contrast study.

Response to medical therapy is also a rational way to diagnose duodenal ulcers or erosions. If the case history strongly suggests ulceration caused by NSAIDs, stress and/or mast cell tumor, it may be reasonable to treat the dog and resort to endoscopy only if the dog does not respond as expected.

Upper GI contrast studies using barium sulfate and multiple positions are usually needed to identify advanced lesions. Ulcers vary in size from several millimeters to 4 cm in diameter.

Barium sulfate may adhere to a mucosal defect or penetrate into an ulcerative crater. A barium contrast study is relatively insensitive, however, and small ulcers or larger defects filled with blood or debris may not be seen. Barium sulfate produces a better contrast study than iodine contrast agents. If a duodenal perforation with peritonitis is likely, there is seldom a need for contrast radiography.

Ultrasonographic features of duodenal ulcers include thickening of the duodenal wall, possible loss of the multi-layer wall structure, the presence of a wall defect or crater, fluid accumulation in the stomach and/or duodenum, and diminished gastric motility.

Endoscopy is still the most sensitive method for diagnosing duodenal ulcers or erosions. Ulcers can be observed along the duodenal wall; however, they may be covered by a poorly distended duodenum, covered by mucous/blood, or the illumination of the endoscope may be diminished by large amounts of ingesta or blood whose dark color may absorb light.

If duodenal erosions are present instead of ulcers, there may be a small spot of fresh or digested blood on the mucosal surface.

If one wipes the blood away with the biopsy forceps, there is renewed bleeding from an erosion. Biopsy samples should be collected from the edge of the duodenal ulcer to rule out neoplasia.

Multiple biopsies of the same location should be taken because superficial inflammation often accompanies neoplasia. Non-lesioned areas should also have surface biopsies taken to identify diffuse disease. No biopsy of the center of the ulcer bed should be obtained. It is often very friable and can be easily perforated by the biopsy forceps. If perforation is known to exist, endoscopy is usually contraindicated because pressurization of the duodenum with infused air during the examination increases contamination of the abdominal cavity with duodenal contents.

Surgery should be performed if a duodenal perforation is suspected or if severe bleeding is discovered. Serial evaluations of the hematocrit and cardiovascular assessment are necessary to determine whether blood loss is sufficient to warrant surgery. Surgery is also indicated if the dog has not responded to appropriate medical therapy that has been administered for at least five to seven days. Duodenal and/or gastric lesions are resected during exploratory laparotomy. Sometimes it is difficult to locate mucosal lesions when examining the serosal surface. A thickening duodenal/gastric wall may be detected, resulting from inflammatory infiltrates in the region of the lesion. Intraoperative endoscopy is helpful in detecting gastric/duodenal lesions, so that if multiple ulcers are present they can all be located.

The goals of medical therapy are to remove the underlying cause if possible, maintain mucosal perfusion, decrease gastric acidity, and protect the ulcer. Fluid therapy is important in dehydrated dogs with duodenal ulcers or erosions to maintain mucosal perfusion. Dogs who are vomiting should be given antiemetics as is recommended for treatment of vomiting in acute gastritis/duodenitis. In addition, food should be withheld at least initially, to avoid stimulation of gastric acid and pepsin secretion. Subsequent dietary management is similar to that recommended for acute gastritis/duodenitis. Drugs commonly used to accomplish these goals include receptor antagonists that block the interaction of the secretagogues with their receptors (H2 receptor antagonists) and sucralfate for protecting ulcerated tissue. Antiulcer therapy should be continued for at least four to six weeks.

Medical management Here are tips for general medical management of duodenal ulceration/perforation.

  • Fluid therapy supplemented with potassium chloride to maintain adequate mucosal perfusion. If added cardiovascular support is needed, consider administering intravenous hetastarch at 10-20 ml/kg over a one- to two-hour time period at a single time. One may need to repeat the hetastarch infusions several times over the next several weeks.
  • Administer antiemetics such as metoclopramide if vomiting exists.
  • Withhold food initially and after vomiting resolves feed a diet formulated for inflammatory bowel disease.
  • Administer H2 receptor antagonists such as famotidine at 0.25-0.5 mg/lb twice a day.
  • Administer sucralfate at 0.5-1 gram total dose given two to four times a day. In dogs with severe blood loss, an initial loading dose of 3 to 6 grams, followed by the lower recommended dose.

Note: When treating gastric or duodenal ulcers with H2 receptor antagonist and sucralfate, one should administer the H2 receptor antagonist first and then the sucralfate 30 to 60 minutes later.

  • Administer antibiotics if perforation and/or inflammatory bowel disease is suspected, such as metronidazole twice a day.
  • Administer, at least initially, daily pain medication as needed (analgesic drugs other than the NSAIDs).
  • Concurrently manage the underlying cause if possible.
  • If inadequate response to medical therapy after five to seven days occurs, then perform an exploratory laparotomy.
  • Remember: Intestinal absorption of drugs and appropriate nourishment may not be occurring well initially - injectable drugs are preferred in the beginning of therapy.

Prognosis: The long-term prognosis in older dogs with duodenal ulceration is guarded to poor. The condition may be controlled, but not actually cured.


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