Portosystemic shunts in dogs and cats: definition, epidemiology and clinical signs of congenital portosystemic shunts

Congenital portosystemic shunts (CPSS) are hepatic vascular anomalies which can affect any breed of dog or cat. Extrahepatic CPSS are most commonly observed in cats and small dogs, whereas intrahepatic CPSS are more likely to affect large breed dogs. A hereditary basis has been observed in some dog breeds. Affected animals are usually presented at young age with a variety of neurological, gastrointestinal, urinary or other signs. Signs of hepatic encephalopathy often predominate. The pathogenesis of this condition is not yet completely understood and is probably multifactorial. The underlying cause is probably the influence on the brain of one or more toxins which normally speaking should be detoxified by the liver. Ptyalism is a very common sign in cats with CPSS.