Idiopathic Eosinophilic Masses of the Gastrointestinal Tract in Dogs

Background: Eosinophilic inflammation of the gastrointestinal tract of dogs occurs in numerous disorders, typically resulting in diffuse intestinal thickening. Rarely, eosinophilic masses have been reported. Objective: Describe a series of dogs with 1 or more idiopathic eosinophilic gastrointestinal masses (IEGM) to better characterize the clinical features, treatment, and prognosis. Animals: Seven dogs with 1 or more gastrointestinal masses composed primarily of eosinophilic infiltrates for which no underlying cause was found. Methods: Retrospective case series. Results: Rottweilers and purebred, large breed dogs predominated. Dogs were middle‐aged and typically had chronic signs of upper or lower gastrointestinal disease. Decreased appetite, vomiting, and evidence of gastrointestinal hemorrhage were present in the majority of cases. An abdominal or rectal mass was frequently noted on physical examination. Common laboratory abnormalities included peripheral eosinophilia, mature neutrophilia, hypoproteinemia, and hypocholesterolemia. The masses were histologically composed of moderate to severe eosinophilic infiltrates, which were often transmural and accompanied by fibrosis. All dogs treated with surgery alone died of complications of their disease. Treatment with corticosteroids and ivermectin improved clinical signs, caused resolution of eosinophilic infiltrates, and prolonged survival in most dogs treated medically. Conclusions and Clinical Importance: These findings suggest that the prognosis for dogs with IEGM may be good when recognized and managed appropriately. When surgery is performed, medical treatment should also be added.