Abstract
Background:
An eleven-year-old male Siberian Husky presented with acute hypovolemic shock on initial physical examination. Serum biochemistry revealed hyperamylasemia and hyperlipasemia. Abdominal ultrasonography identified a well-defined, round, lobulated 10.0 cm mass caudal to the stomach. A large volume of hyperechoic peritoneal fluid was detected in the abdominal cavity. The peritoneal fluid packed cell volume (PCV) was similar to the peripheral PCV, confirming hemoperitoneum.

Case Description:
Surgical resection of the mass and damaged pancreatic vessels was performed. Adherent mesenteric blood vessels and a segment of the jejunum were also removed due to their association with the mass, followed by jejunal anastomosis. No abnormal clinical signs were observed postoperatively. A definitive diagnosis of pancreatic acinar cell tumor was made based on histopathological findings. The patient remained clinically stable without evidence of recurrence for over eleven months after surgery.

Conclusion:
This report is the first documented case describing successful surgical management of nontraumatic hemoperitoneum secondary to pancreatic acinar cell carcinoma in a dog. Histopathological evaluation confirmed a moderately well-differentiated pancreatic acinar cell carcinoma. This case suggests that timely diagnosis and intervention may improve outcomes in patients with hemorrhagic presentations of pancreatic neoplasia.

Key words: Pancreatic acinar cell carcinoma, Hemoperitoneum, Surgical management, Dog