A challenging case: Acute-on-chronic vomiting in a German shepherd - Veterinary Medicine
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A challenging case: Acute-on-chronic vomiting in a German shepherd
These clinicians discover that this dog's history of chronic vomiting was disguising a serious underlying problem.


VETERINARY MEDICINE


DIAGNOSTIC TESTS AND DIAGNOSIS


Table 1 : Laboratory Test Results
We performed a complete blood count, a serum chemistry profile, a urinalysis, and an abdominal and thoracic radiographic examination. The complete blood count (Table 1) revealed an elevated hematocrit, an elevated hemoglobin, an elevated red blood cell count, and a leukocytosis with a segmented neutrophilia, lymphopenia, and monocytosis. Abnormal results of the serum chemistry profile (Table 1) included an elevated blood urea nitrogen concentration, hypokalemia, and hypochloremia. These findings were attributed to and consistent with vomiting, anorexia, and dehydration. The elevated blood glucose concentration was most likely a physiologic response (glucocorticoid-associated) to stress.

The results of a urinalysis on a sample collected by cystocentesis revealed a specific gravity of 1.052 (reference range = 1.015 to 1.045), mild hematuria (3+ blood), and mild proteinuria (4+ protein). The urine specific gravity indicated that the dog was concentrating urine appropriately in the face of dehydration. We attributed the hematuria to the collection method, and we did not consider the proteinuria to be clinically relevant because the urine was concentrated and hematuria was present. We submitted a urine sample for bacterial culture, which resulted in no growth.


Figures 1-4
The lateral and ventrodorsal abdominal radiographs revealed a cranially displaced spleen. At the cranial edge of the lateral radiograph, part of the caudal thorax was visible, revealing a large soft tissue structure (Figure 1). The stomach was not visible within the abdomen. The thoracic radiographs demonstrated severe gas distention of the cranial thoracic esophagus, consistent with megaesophagus; microcardia was also present (Figures 2-4). An ovoid, 14- x 18-cm soft tissue mass was present on the midline in the area of the caudal thoracic esophagus (Figure 3).

Based on the radiographic findings, we diagnosed a gastroesophageal intussusception. Our other differential diagnoses were a paraesophageal hernia, a hiatal hernia, an esophageal luminal mass, and a foreign body. Paraesophageal and hiatal hernias were less likely because the mass appeared to be an intraluminal esophageal mass. An esophageal mass such as a granuloma or neoplasia seemed less likely than a gastroesophageal intussusception because the stomach could not be seen in the abdomen. The severe megaesophagus was most likely a congenital or acquired condition, and megaesophagus can be a predisposing factor for a gastroesophageal intussusception. The intussusception could only have been present for a short time. The microcardia was consistent with hypovolemia.

TREATMENT

We initiated intravenous fluid therapy (380 ml/hr) with lactated Ringer's solution to stabilize the dog hemodynamically before performing abdominal exploratory surgery, which was scheduled for early the next morning. General anesthesia was induced with propofol (5 mg/kg intravenously) and maintained with isoflurane. Positive pressure ventilation was required. We initiated an intravenous continuous rate infusion of fentanyl (5 g/kg/hr) and lidocaine (50 g/kg/hr).

A ventral midline incision was made from the xiphoid to the pubis. On exploration, the stomach was completely invaginated within the esophagus; the duodenum was the first portion of the gastrointestinal tract located on the abdominal side of the diaphragm. No other organs were displaced into the esophagus. The esophageal hiatus had no visible abnormalities. The spleen was displaced cranially. Gentle traction was applied to reduce the stomach into its normal position, but a diaphragmatic incision about 2 cm in length at the level of the esophageal hiatus was required to reduce the stomach into the abdominal cavity. A ventral longitudinal incision in the esophagus about 2 cm wide was also made to free the congested stomach.

Once the stomach was reduced, its viability was assessed. The serosal surfaces of the fundus and cardia were dark-red to purple. The pyloric antrum and pylorus were normal in color. The wall of the stomach felt slightly thickened, and wall motility was normal, so stomach resection was deemed unnecessary. The spleen looked grossly normal and was no longer displaced. The rest of the abdominal exploratory surgery revealed no other abnormalities.


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Source: VETERINARY MEDICINE,
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