These tumors result in autonomous gastrin secretion as a result of malignant transformation of somatostatin-secreting delta cells of the endocrine pancreas to gastrin-producing cells.
Unregulated secretion of gastrin stimulates excessive secretion of gastric acid, resulting in esophageal and gastroduodenal erosions and ulcerations. Additionally, gastric antral hypertrophy may result in gastric outflow tract obstruction.
Over a lengthy period of time, severe gastric and proximal small intestinal ulceration develops. This disease can be further complicated by obstruction of the common bile duct in cases of gastrinomas situated in the duodenum.
Clinically affected dogs often present with a primary symptom of persistent severe vomiting, diarrhea, anterior abdominal pain, melena, inappetence and weight loss. Rarely, regurgitation may be seen as a result of severe esophagitis. Small breed dogs appear to be more frequently diagnosed.
Contrast radiographs are of limited value but ultrasonography may reveal a hyperechoic mass situated within the pancreas.
Blood analysis usually reflects a marked, acute leucogram and hypergastrinemia.
Diagnosis is usually based on histopathology and immunohistochemistry demonstrating the presence of a gastrin-producing pancreatic carcinoma. Additional testing is based on the demonstration of low gastric pH (< 3) and concurrently high gastrin levels. Concurrent gastrinoma and somatostatinoma have also been reported in dogs.
Treatment includes use of proton pump inhibitors (e.g. omeprazole), gastro-protectants (famotidine, sucralfate and misoprostol) and somatostatin analogs (octreotide) to suppress gastrin secretion.
Surgical resection of the gastrin-secreting tumor is the treatment of choice but does not provide a cure due to the metastatic nature of this carcinoma.
Long-term prognosis is poor, and survival times range from 1 to 36 months.
- Gal A et al (2011) An unusual clinical presentation of a dog with gastrinoma. Can Vet J 52(6):641-644
- Rousseaux CG (1987) Ultrastructure of a canine gastrinoma. J Comp Pathol 97:605
- Straus E et al (1977) Canine Zollinger-Ellison syndrome. Gastroenterology 72:380–381
- Vergine M et al (2005) Common bile duct obstruction due to a duodenal gastrinoma in a dog. Vet J 170(1):141-143
- Happe RP et al (1980). Zollinger-Ellison syndrome in three dogs. Vet Pathol 17:177–186
- Hughes SM (2006) Canine gastrinoma: A case study and literature review of therapeutic options. N Z Vet J 54:242–247
- Fukushima U et al (2004) A case of gastrinoma in a Shih-Tzu dog. J Vet Med Sci 66(3):311-313
- Robben JH et al (2005) Comparison of ultrasonography, computed tomography, and single-photon emission computed tomography for the detection and localization of canine insulinoma. J Vet Intern Med 19(1):15-22
- Hoenerhoff M & Kiupel M (2004) Concurrent gastrinoma and somatostatinoma in a 10-year-old Portuguese water dog. J Comp Pathol 130:313–318
- Fukushima R et al (2004) A case of canine gastrinoma. J Vet Med Sci 66(8):993-995
- Hoenerhoff M & Kiupel M (2004) Concurrent gastrinoma and somatostatinoma in a 10-year-old Portuguese water dog. J Comp Pathol 130(4):313-318
- Brooks D & Watson GL (1997) Omeprazole in a dog with gastrinoma. J Vet Intern Med 11:379–381
- Mordecai A et al (2011) Normal dogs treated with famotidine for 14 days have only transient increases in serum gastrin concentrations. J Vet Intern Med 25(6):1248-1252
- Altschul M et al (1997) Evaluation of somatostatin analogues for the detection and treatment of gastrinoma in a dog. J Small Anim Pract 38:286–291
- Ward CR & Washabau RJ (2005) Gastrointestinal endocrine disease. In: Ettinger SJ, Feldman EC, editors. Textbook of Veterinary Internal Medicine. 6th ed. St. Louis, Missouri: Elsevier Saunders. pp:1629–1631