Adenocarcinoma gástrico atípico em cão da raça Dachshund

This report describes a case of atypical gastric adenocarcinoma in a 5-year-old male Dachshund from the city of Brumado, Bahia (Brazil). The patient presented with clinical signs consistent with gastritis that were unresponsive to conventional treatment, including vomiting and progressive weight loss. The initial histopathological examination did not detect the presence of neoplasia. However, after the clinical condition worsened and euthanasia was performed, post-mortem endoscopy and a subsequent histopathological analysis confirmed the diagnosis of gastric adenocarcinoma. This case is noteworthy due to the absence of a known breed predisposition, the patient's unusually young age, and the ulcerative nature of the lesion which differs from the typical presentation as masses or polyps.