Clinical Conditions of the Liver and Pancreas
Hepatitis is an inflammatory condition of the liver. In dogs infectious canine hepatitis is caused by Canine mastadenovirus A (formerly called Canine adenovirus 1 [CAV-1]). The clinical signs of pyrexia, jaundice, vomiting and signs of encephalopathy are typical of canine hepatitis and usually resolve after a brief illness.
Most dogs receive an effective vaccine. In the large domestic animals, hepatitis is usually due to ingested plant toxins, e.g. ragwort.Portosystemic shunts (PSSs) are of regular occurrence in dogs and cats. A PSS is the presence of vascularity that bypasses the liver, allowing blood from the hepatic portal vein to go directly to the caudal vena cava. This abnormality results in the inability of the liver to deal directly with toxins, proteins, hormones and nutrients absorbed by the intestines. Most PSSs are congenital in origin and result in neurological signs, e.g. seizures, unsteadiness and blindness. Surgical treatment of PSSs usually involves complete or partial occlusion of the abnormal vessel.
Cattle, sheep, deer and horses may be infected with liver fluke (Fasciola hepatica). This is a parasite with the snail (Galba truncatula) as the intermediate host. The domestic animals ingest the larvae when grazing pasture during the autumn. The oval-shaped flukes, up to 3 cm long, penetrate the gut wall and migrate in the bloodstream to the liver. Affected animals lose condition, become anaemic and develop ‘bottle jaw' - oedema under the mandible. Treatment usually involves the oral administration of an anthelmintic drug (e.g. triclabendazole).
Inadequate production of insulin by beta cells in the pancreas islets results in inefficient metabolism of sugars, fats and proteins. This condition is called diabetes mellitus and occurs in dogs and cats. Overweight individuals and those with inflammation of the pancreas are predisposed to developing diabetes. Long-term therapy with corticosteroid drugs can result in iatrogenic diabetes. Diagnosis of diabetes is made by finding sugar in the urine and an increase in blood sugar. Diabetes is usually treated by the regular (once or twice daily) subcutaneous administration of insulin.