Educational use only — not a substitute for professional medical or veterinary advice.

For educational purposes only. This page does not provide medical or veterinary advice, diagnosis, or treatment. Always consult a qualified healthcare or veterinary professional before making any health-related decisions.

Trematode (flatworm/fluke)HumanDogCat

Liver Fluke

Fasciola hepatica / Fasciola gigantica

Size: Visible to naked eye — adults 2–3 cm (Fasciola hepatica up to 5 cm)

Prevalence

Estimated 2.4–17 million people infected worldwide; 180 million at risk; endemic in over 70 countries

Liver flukes are parasitic flatworms that infect the bile ducts and liver of their hosts. Fasciola hepatica is the most widespread species, found on every continent except Antarctica. Infection occurs by eating aquatic plants (especially watercress) contaminated with encysted larvae (metacercariae). While primarily a disease of livestock (sheep, cattle), it is an increasingly recognized human and pet pathogen. Chronic infection can cause serious liver damage and bile duct obstruction.

Lifecycle

Adult flukes in the bile ducts produce eggs that pass in feces into water. Eggs hatch into miracidia that infect freshwater snails (Lymnaea spp.). Inside the snail, the parasite multiplies and eventually releases cercariae that encyst on aquatic vegetation as metacercariae. Hosts are infected by ingesting contaminated plants or water. Larvae migrate through the intestinal wall, across the peritoneum, and into the liver, causing significant tissue damage before reaching the bile ducts where they mature.

Liver Fluke — Fasciola hepatica / Fasciola gigantica

Liver FlukeFasciola hepatica / Fasciola gigantica

Symptoms

Acute phase (larval migration): fever, right upper abdominal pain, nausea, vomiting
Hepatomegaly (enlarged liver) and tenderness
Eosinophilia (elevated eosinophils in blood — a key diagnostic clue)
Urticaria (hives) and skin rash
Chronic phase: intermittent right upper quadrant pain
Bile duct obstruction: jaundice, dark urine, pale stools
Cholangitis (bile duct inflammation) and cholecystitis
Weight loss and fatigue in chronic infections
In dogs and cats: weight loss, lethargy, jaundice, ascites (fluid in abdomen), diarrhea

Pharmaceutical treatments

Evidence-based medications used by healthcare and veterinary professionals.

Reference only. Medication names, types, and notes are provided for general awareness. Dosage, suitability, and prescribing decisions must be made by a licensed physician or veterinarian.

Triclabendazole (Egaten)

Prescription

Drug of choice for human fascioliasis. Single dose of 10 mg/kg (or two doses of 10 mg/kg 12 hours apart for severe infections). FDA-approved in 2019. Highly effective against both juvenile and adult flukes.

Nitazoxanide

Prescription

Alternative when triclabendazole is unavailable. 500 mg twice daily for 7 days. Less effective than triclabendazole but may be used in resource-limited settings.

Praziquantel

Prescription

Not effective against Fasciola hepatica (unlike most other flukes). Do not use as a substitute for triclabendazole for liver fluke infections.

Triclabendazole (veterinary — Fasinex)

Veterinary Prescription

Used in dogs and cats under veterinary supervision. Dosing varies by species and severity. Supportive care (fluids, nutritional support) important in severe cases.

Holistic & natural approaches

Traditional, herbal, and integrative approaches for general awareness.

Not a substitute for medical treatment. Natural remedies listed here have not been evaluated by the FDA or equivalent regulatory bodies. Do not use these in place of prescribed treatment. Always consult a qualified healthcare or veterinary professional first.

Milk thistle (Silybum marianum)

Silymarin has hepatoprotective properties and may help support liver recovery during and after fluke infection. Available as capsules or tincture. Used as a supportive supplement alongside conventional treatment — not a replacement.

Dandelion root

Traditional liver tonic with mild choleretic (bile-stimulating) properties. May support bile flow and liver function during recovery. Available as tea or tincture. Supportive use only.

Turmeric (Curcumin)

Anti-inflammatory and hepatoprotective properties. Some laboratory studies suggest activity against trematodes. May help reduce liver inflammation during infection. Take with black pepper (piperine) to improve absorption.

Dietary support

A low-fat diet reduces bile duct stress during active infection. Increase antioxidant-rich foods (berries, leafy greens) to support liver recovery. Avoid alcohol entirely during treatment and recovery.

Prevention

Do not eat raw watercress or other aquatic plants from potentially contaminated water sources
Wash all aquatic vegetables thoroughly — cooking destroys metacercariae
Avoid drinking untreated water from streams, ponds, or irrigation channels
Control freshwater snail populations in livestock areas
Regular fecal testing and veterinary deworming of dogs and cats in endemic areas
Wear gloves when handling potentially contaminated soil or vegetation
Travelers to endemic regions (South America, Africa, Asia, parts of Europe) should avoid raw aquatic plants

Zoonotic risk — can spread between animals and humans

Fasciola hepatica is a true zoonosis — humans, dogs, cats, and livestock all share the same parasite species. The primary route of human infection is eating contaminated aquatic plants, not direct contact with infected animals. However, infected livestock and pets contribute to environmental contamination through fecal egg shedding.

This information is for educational purposes only and is not a substitute for professional medical or veterinary advice. If you suspect a parasitic infection, consult a qualified healthcare or veterinary professional.