Liver abscesses in feedlot cattle .1. Causes, pathogenesis, pathology, and diagnosis

Liver abscesses result from the entry and establishment of pyogenic bacteria. Bacteria gain access to the liver via direct extension or via the portal vein, hepatic artery, umbilical vein, or bile duct system. Direct extension of infection from adjacent tissues and organs is usually of traumatic origin. Entry via the portal vein is by far the most frequent because of its large volume of blood flow and the fact that it drains the gastrointestinal tract. Liver abscesses can occur in cattle of all ages and types (including dairy cows); the abscesses of greatest economic significance occur in grain-fed cattle. The condition is reported most commonly in intensively feed beef cattle.