Gastroesophageal intussusception (GEI), a potential life threatening condition in dogs, has been described infrequently in Veterinary literature⁵. In almost all cases, it was secondary to megaesophagus of caudal part of the thoracic oesophagus². The condition has not been reported from India, though cases of variable degree of megaesophagus are not uncommon⁶. Hence the present case is being put on record.

A carcass of Doberman bitch, about 5 months of age was received for postmortem examination at the Division of Pathology of the Institute. The clinical history revealed that the bitch although appeared normal, active and alert, but it had started vomiting and regurgitating food, which became occasionally blood mixed about 20 days back. Water and milk intake was normal. It was treated symptomatically with enteric antibiotics, occasional fluid therapy and oral antacids. Clinically, the case was diagnosed as of megaesophagus about 8 days prior to death. Exploratory laparotomy at the polyclinic showed all the abdominal organs normal and in situ. Regurgitation of food and hematemesis continued. The animal became very weak and dehydrated but was responsive till shortly prior to death.

Grossly, the carcass was in highly cachectic and dehydrated condition having shrunken eyes with pale whitish conjunctiva. Visible mucous membranes were anaemic. The abdominal organs were pale. The entire stomach, with spleen and anterior half of duodenum were not seen in abdominal cavity. The pancreas was at the hiatus of oesophagus and the duodenum and part of gastric omentum were seen pushed into the thoracic cavity through the hiatus oesophagi (Fig.1). Diagphragm was normal. No anatomical abnormality was noticed in other abdominal and pelvic organs. The intestines were practically empty except little yellowish brown mucus mixed material.

The cervical oesophagus was dilated uniformly with thin, collapsed and flaccid wall having flattening of mucosal folds. The lumen contained little brownish mucoid material. No other pathological lesion was noticed in the wall of oesophagus. The caudal thoracic oesophagus was greatly dilated and was choked with a soft mass, 10.5 cm with largest diameter of 20 cm, that displaced the lungs which were collapsed. Heart was found at normal anatomic position. The careful incision of oesophageal wall exposed the inverted stomach which formed the intraesophageal mass. The gastric mucosal folds were in apposition with practically flattened oesophageal mucosal surface and revealed little brownish yellow mucoid material and a few blood clots attached to it (Fig. 2). The gastric cardia was seen inverted at the hiatus as glistening white band. The gastric wall, on incision, exposed the entrapped spleen centrally and the anterior segment of duodenum (6 cm) ventrally and the cavity created by the serosal surface of the inverted stomach contained yellowish brown thin fluid (Fig.3). The duodenal mucosa was oedematous with glistening surface. The lumen of pylorus located anteriorly to the inverted stomach and the duodenum was practically empty except little slimy yellowish brown but transparent fluid material. The case was diagnosed as gastroesophageal intussusception (GEI). The gross pathological findings were similar to those reported by Geoffrey et al.² in a German Shephered dog. The present case was in a Doberman bitch of 5 months of age. Leib and Blass⁵ reviewed cases of GEI and reported 81.8% of dogs to be <3 months old and only 1 was older than 1 year and 60.9% cases were in German shephered dogs who also had high incidence of megaesophagus, a condition that may predispose dogs to GEI. Segmental dilatation of oesophagus with achalasia in 72.7% and generalised hypomotility with dilation and achalasia in 25.0% dogs out of 44 cases examined radiographically were noticed. Extremely high mortality (95.7%) with clinical manifestations of frequent vomiting or regurgitation, hematemesis and deterioration of body condition as observed in the present case has been reported in cases of GEI⁵.

The present case appeared to be secondary to congenital megaesophagus where symptoms of regurgitation of solid food developed gradually¹,³. Though the pathogenesis of congenital megaesophagus is poorly understood but the delay in maturation of esophageal nervous innervation due to some lesion in the upper motor neurons of the central swallowing centre or in the afferent sensory arm of the reflex involved with peristalsis could have been responsible,³,⁴. This might result in failure of peristaltic propulsion of the food bolus to and through the lower oesophageal sphincter of the stomach. Gradually the volume of the dilated thoracic oesophagus might exceed that of the stomach⁴ and the forceful reverse peristalsis in the empty stomach wall could cause stomach to get inverted from its pyloric end and get pushed along with spleen, duodenum and part of omentum through the hiatus into the dilated caudal part of thoracic oesophagus. The frequent vomiting or regurgitation of food and hematemesis might cause malnutrition, dehydration and anaemia leading to extreme degree of emaciation in the affected dogs. The condition of GEI in present case appeared to have developed few hours prior to death as grossly the compression lesions of extreme degree did not develop except oedema.

Fig. 1:Caudal duodenum and part of gastric omentum seen pushed through the hiatus esophagi (arrow) in diaphragm (D).

Fig. 2:Inverted stomach within the lumen of dilated oesophagus. Note the attached blood clots on gastric mucosal surface (arrow).

Fig. 3:Incised gastric mucosa exposing the trapped spleen (S) in the centre and cervical duodenum (D).

Gastroesophageal intussusception in a doberman dog: A rare condition