Gastric emphysema and pneumatosis intestinalis in two common marmosets with duodenal dilation syndrome

Abstract Background Common marmosets (Callithrix jacchus) are widely used as primate experimental models in biomedical research. Duodenal dilation with chronic vomiting in captive common marmosets is a recently described life-threatening syndrome that is problematic for health control. However, the pathogenesis and cause of death are not fully understood. Case presentation We report two novel necropsy cases in which captive common marmosets were histopathologically diagnosed with gastric emphysema (GE) and pneumatosis intestinalis (PI). Marmoset duodenal dilation syndrome was confirmed in each case by clinical observation of chronic vomiting and by gross necropsy findings showing a dilated, gas-filled and fluid-filled descending duodenum that adhered to the ascending colon. A diagnosis of GE and PI was made on the basis of the bubble-like morphology of the gastric and intestinal mucosa, with histological examination revealing numerous vacuoles diffused throughout the lamina propria mucosae and submucosa. Immunostaining for prospero homeobox 1 and CD31 distinguished gas cysts from blood and lymph vessels. The presence of hepatic portal venous gas in case 1 and possible secondary bacteremia-related septic shock in case 2 were suggested to be acute life-threatening abdominal processes resulting from gastric emphysema and pneumatosis intestinalis. Conclusions In both cases, the gross and histopathological findings of gas cysts in the GI tract walls matched the features of human GE and PI. These findings contribute to clarifying the cause of death in captive marmosets that have died of gastrointestinal diseases.