Fasciola hepatica, or the liver fluke, is a parasitic flatworm that infects livestock like cattle and sheep and causes significant economic losses. It has a complex lifecycle involving an intermediate snail host and affects animals by causing anemia, weight loss, and liver damage. Diagnosis involves examining feces for eggs of the parasite. Treatment of infected animals includes dewormers like albendazole or triclabendazole. Preventing exposure by controlling snail populations and removing animals from flooded pastures can also limit the spread of this parasitic infection.

1. Prevalence of fasciola hepatica in domesticated animal and its prevention and control
Fasciola hepatica also called (Liver fluke) is a parasitic disease caused by infection of trematode
belongs to genus (F. hepatica, F. gigentica). Fasciola hepatica is distributed worldwide and
cause great economic loss in livestock sector. Infected animal become anemic and loss of
significant amount of weight.
Fasciola hepatica is mainly found in hilly area and F. gigentica is mainly found in planes area
and restricted to warmer region.
Definitive host: sheep/ cattle, human (Accidental)
Intermediate host: fresh water snail (genus: Lymnaea)
The common species of trematode are:
1. Fasciola hepatica (liver fluke)
2. Fasciola gigentica (liver fluke)
3. Fasciolopsis buski (intestinal fluke)
4. Fasciola indica (liver fluke)
5. Paramphistome cervi ( stomach fluke)
6. Schistosomiasis (Nasal granuloma)
How animal infected by F. hepatica?
When heavy rain or flood in rainy season, the pasture is heavily contaminated encyst cercariae.
Snail are the intermediate host and multiply very rapidly in water. The animal are attracted by
lush, green grasses around the pond, stream and other water sources full of snail and get
themselves infected.

2. Life cycle of liver fluke:
 The lifecycle of F.hepatica start when a female laid egg in the liver of infected animals.
 Immature egg are discharge in the billary duct and taken out in the feces.
 If they landed in water, the egg become embryonated and develop larvae called
miracidium.
 Meracidium find its host which is snail and convert into sporocyst, rediae, and cercariae
in snail.( larvae which is capable of swimming with its large tail).
 Cercariae should be converted into metacercariae and this metacercariae through
vegetation ingested by cattle, goat, sheep and other host.
 Then metacercariae goes into the first part of small intestine, duodenum. Then it’s
penetrated the intestinal wall and gets into peritoneal cavity and the larva goes into the
liver.
 And start to eating liver cell. Usually the larvae spent a few weeks just browsing and
eating the liver. It takes about 3 month for metacercariae to develop into adult.
Parasite weakens the immune system of animal, as they suck the blood and get nutrient from the
host. During migration the flukes are immature but it becomes mature in liver and bile duct.
Mature flukes lay egg, pass into feces and cycle start again. Adult female can produce up to 2500
eggs per day.
Clinical sign and symptoms:
F. hepatica is a zoonotic disease. The clinical sign include high fever, profuse diarrhea, loss of
weight, sub mandibular edema (bottle jaw), pale mucus membrane, anemic condition, reduce
milk production, poor fertility and debilitation.

3. Acute fascioliasis: This stage is mostly common in sheep and goat but not common in cattle and
other large animal. Lack of appetite, weakness, edema of mucosa and conjunctiva are common
sign of this stage. Also cause traumatic hepatitis, and fibrosis clot on liver surface is seen, liver
enlarge.
Chronic fascioliasis: in this stage, this is most common type of fascioliasis which is found in all
type of animal of all age including man also. Sign include, anemic with rough andoffcoloured
skin coat. Mucus membrane becomes pale and skin become dry, sub mandibular edema (bottle
jaw), milk production decrease and chronic diarrhea may occur.
Fig:1.Profuse diarrheaingoat
Fig:2.Body emaciation

4. Diagnosis:
Generally F. hepatica is diagnosis by fecal test, such as sedimentation or centrifugation for the
detection of egg.
It also depends on the history of snail habitat or fascioliasis on the farm, clinical symptoms, post
mortem examination, blood examination etc...
Fig: 6. Fasciola hepatica Fig:7. Fasciola buski
Treatment and prevention:
Albendazole 7.5 mg /kg bwt in small animal and 10 mg/kg bwt large animal is effective against
adult flukes.
Triclabendazole is specific compound for use against F. hepatica in sheep and cattle.
Oxyclozanide is used only in cattle, and is mainly effect against adult worms but inactive against
immature fluke. Dose: 10 to15 mg/kg bwt.
Fig:3.Pale mucusmembrane Fig:4.Sub mandibularedema(bottle jaw) Fig:5. Administerfluidtherapy

5. Prevention:
1. As we know that snail is intermediate host so that infective stage of snail is meracidium
and infective stage for final host is metacercariae. So if we break the cycle of these 2
stages so that we can prevent this disease.
2. Control the population of snail.
3. Use deworming regularly.
4. It is essential to remove animal form infected pasture. They should not be allowed to
graze on flood inundated pasture.
Author: Dr. Manoj karki (BVSC&AH)
Fig:8.Albendazolebolus-600mgfordeworming