Dogs with liver disorders often display gastrointestinal signs that may be triggered by ulceration. The liver is important for inactivation of some forms of gastrin. Therefore, hypergastrinaemia has been implicated in the pathogenesis of gastrointestinal ulcerations related to liver dysfunction. The aim of this study was to determine serum gastrin concentrations in dogs with liver disease. Fasted blood samples were collected from 15 dogs with newly diagnosed liver disease and 18 healthy dogs. Gastrin concentrations were significantly lower in dogs with congenital portosystemic shunt compared with healthy dogs (P=0.003). No significant difference (P=0.6) in gastrin concentration was revealed between dogs with hepatocellular disease and healthy dogs. Serum gastrin concentrations were not significantly associated with the occurrence of vomiting, anorexia, diarrhoea, or melaena in dogs with liver disorders. These findings did not provide support for the role of hypergastrinaemia in the development of gastrointestinal signs associated with liver disease in dogs. Decreased serum concentrations of gastrin in a dog with liver disease may suggest the presence of portosystemic shunt. Further investigation is warranted to determine the importance of hyopogastrinaemia in congenital postosystemic shunts in dogs and to evaluate potential alterations in serum gastrin concentrations in specific hepatocellular diseases.