Liver Fluke Information

Liver flukes commonly infect grazing animals but can also be transmitted to other species, including humans. Ingested larvae travel to the liver and reproduce in the bile ducts, releasing eggs into the digestive system, which are expelled into the environment.

  1. Life-Cycle

    • Snails eat fluke eggs in the environment and several larval stages progress within the snail. Young flukes emerge from snails and encyst onto grass, which other animals eat. The ingested juveniles burrow through the intestine and into the liver, where they reproduce in the bile ducts.

    Symptoms

    • A few flukes do not cause clinical signs but many flukes migrating together cause liver damage. Signs of damage include diarrhea, weight loss and jaundice. The flukes predispose animals to secondary bacterial Clostridium infections, or Redwater, which causes death.

    Diagnosis

    • Fecal exams detect fluke eggs but egg numbers vary from day to day. Therefore, repeated fecal exams may be required. Liver enzyme analysis detects bile duct damage and organ analysis at death reveals adult flukes.

    Treatment

    • Several drugs are available as treatments for liver flukes, although long withdrawal periods are required for meat-producing animals. Some animals may need bile thinners or bile duct surgery to assist in proper bile duct function.

    Control

    • Removing flukes from infected animals, reducing snail populations and preventing access to infested pastures will reduce liver fluke incidence. Cooking infested aquatic animals prior to consumption prevents flukes in cats, dogs and humans.