A case of gastric adenocarcinoma in a Shih Tzu dog: successful treatment of early gastric cancer.

A 9-year-old castrated male Shih Tzu dog was referred to us, because of chronic vomiting. The patient's hematological, radiographic, ultrasonographic, endoscopic and histological examinations were evaluated for diagnosis. Hematologic analysis indicated moderate anemia and azotemia. Based on the imaging studies, an oval-shaped mass was identified in the gastric pylorus area. A proliferative mass was found on endoscopic examination, and we performed biopsy using grasping forceps. The histopathological findings of the biopsy specimens indicated hypertrophic gastritis, and Y-U pyloroplasty was performed. However, histopathological examination of the surgically resected mass revealed tubular adenocarcinoma of the stomach. Then, carboplatin chemotherapy was performed 4 times for 13 weeks. Clinical signs, such as vomiting, were resolved gradually after surgery and chemotherapy, and the patient's condition was managed favorably until recently (30 months after surgery). This case report describes clinical features, imaging studies, endoscopic characteristics and histopathological and immunohistochemical features of gastric tubular adenocarcinoma as early gastric cancer in a dog.