This document summarizes information on various trematode parasites (flukes), including their life cycles, hosts, sites of infection, symptoms, diagnosis, treatment, and control methods. It describes several flukes that can infect humans, livestock, dogs, and other animals. For each fluke, it provides brief details about the intermediate and final hosts, the life cycle stages within those hosts, associated signs or symptoms of infection, how diagnosis is made, treatments available, and recommended control approaches.

1. 1 | P a g e W w w . R C V e t S . c o m
Helminthology: Trematodes
Organism
Final Host Site of
Infection
Life Cycle
Symptoms/
Signs
Diagnosis Treatment Control
Intermediate
Fasciola hepatica
(Liver Fluke)
Sheep, Cattle,
Human Intestine,
Liver
Eggs → Miracidia →
Sporocyst→ Rediae→
Cercariae→
Metacercariea
Abdominal pain, Anemia,
Hepatic Tenderness, Jaundice,
Hepatomegaly,
Lethargy, Nausea
Fecal Examination,
Serology, Ultrasound, CT
Scan.
Triclabendazole,
Bithionol,
Surgery
Molluscicides,
Chemotherapy.
Snail
Heterophyes
heterophyes
Dog, Cat, Man
Small
Intestine
Eggs (Snail) → Miracidia
→ Sporocysts →
Rediae→ Cercariae
(Fish) → Metacercariae
Inflammatory reaction at the
site of contact of Intestine,
Intestinal Pain & Diarrhea,
heart Failure & Neurological
disorders.
Fecal Examination
Quinolone,
Praziquantel,
Tetrachloride.
Avoid use of raw &
improperly cooked
fish in food.
Snail & Fish
Paramphistomum
cervi
Ruminants
Rumen
Eggs → Miracidium →
Cercariae →
Metacercariae
Diarrhea,
Weakness,
Dehydration, Anorexia,
Hyperplasia, Edema,
Death occurs in 15-20 days.
Immature Flukes in Feces,
ELISA,
Necropsy.
Oxyclosanide,
Hexachlorophene,
Niclosamide
Molluscicides,
Treatment b/w the
seasonal peaks,
Drainage & Fencing of
affected areas.
Snail
Prosthogonimus
macrorchis
(Oviductal Fluke)
Poultry, Birds,
rarely
mammals.
Bursa of
fibricious,
Oviduct,
Gut.
Eggs → Cercariae →
Metacercariae
Oviductal inflammation,
Abnormal eggs,
Discharge of albumin from
cloaca.
Detection of egg in cloacal
discharge (Eggs are Shell-
less and smaller in size than
other helminthes).
Flubenet (1%),
Tetrachloroethylene,
Nicoflan,
Praziquantel,
Albendazol.
Elimination of
Intermediate host.
Snail &
Dragon Fly
Dicrocoelium
dendriticum
(Lacent Liver
Fluke)
Cattle, Sheep,
Goat, Human.
Bile Duct
Egg → Miracidium
(Snail) → Sporocyst →
Cercariae → Slime ball
(Ant)→ Metacercariae
Anemia, Edema, Cirrhosis of
Liver, Emaciation
Egg in Feces.
Albendazol,
Thiabendazole,
Tricabendazole,
Praziquantel.
By destruction of
intermediate host.
Land Snail &
Ant
Eurytrema
pancreaticum
Sheep, Goat,
Buffalo. Bile Duct &
Duodenum.
Eggs → Miracidium
(Snail) → Sporocyst →
Cercariae (Grasshopper)
Inflammation, Necrosis and
Fibrosis of pancreatic duct.
Egg in Feces
Albendazole,
Praziquantel.
Control Intermediate
HostSnail and
Grasshopper

2. 2 | P a g e W w w . R C V e t S . c o m
Helminthology: Trematodes
Organism
Final Host Site of
Infection
Life Cycle
Symptoms/
Signs
Diagnosis Treatment Control
Intermediate
Paramphistomum
explanatum
Human,
Ruminants Bile Duct.
Egg → Miracidium
(Snail) → Cercariae →
Metacercariae
Anorexia, Weakness, Diarrhea Necropsy, ELISA
Oxyclosanide,
Hexachlorophene.
Intermediate host.
Remove animal from
infective pasture.Snail
Cotylophroum
cotylophroum
(Rumen Fluke)
Cattle, Buffalo
Rumen &
Reticulum
Egg → Miracidium
(Snail) → Sporocyst →
Cercariae →
Metacercariae
Gastroenteritis, Diarrhea Egg in Feces.
Tricabendazole,
Oxyclosanide.
Molluscicide
Snail
Paragonimus
westermanii
(Lung Fluke)
Dos, Cat,
Goat, Cattle,
Human
Lungs,
rarely in
Brain &
Spinal cord.
Egg → Miracidium
(Snail) → Sporocyst →
Rediae → Daughter
Rediae → Cercariae
(Crustacean) →
Metacercariae
Bronchial cough, Paroxysmal
coughing, Diarrhea,
Hemiplegia, Monoplegia.
Sputum & Decal
Examination.
Praziquantel,
Nicoflan,
Albendazole,
Sulfadiazine.
Molluscicide,
Cooking of
Crustaceans before
consumption.
Snail &
Crustacean
Fasciolopsis buski
(Giant Intestinal
Fluke)
Human, Pigs
Small
Intestine.
Eggs → Miracidium
(Snail) → Cercariae →
Metacercariae
Inflammation, Ulceration &
Abscesses in Small Intestine.
Edema.
Oval yellow brown eggs in
feces (150*90 microns).
Praziquantel,
Thiabendazole,
Oxyclosanide,
Hexachlorophene.
Immersion of
vegetables in boiling
water for few seconds
to kill infective
Metacercariae.
Snail
Clonorchis
sinensis
(Chinese Liver
Fluke)
Human, Dog,
other Fish
eating
Carnivores.
Liver,
Spleen
Eggs → Miracidium
(Snail) → Cercariae
(Fish) → Metacercariae
Jaundice, Hepatomegaly,
Abdominal pain,
Diarrhea,
Anorexia.
Eggs in Feces.
Praziquantel,
Tribendimidine.
Education,
Molluscicide.
Snail & Fish
Metagonimus
yokogawai
Dogs, Cats,
Pigs. Small
Intestine.
Egg → Miracidium →
Sporocyst → Rediae →
Cercariae (Fish) →
Metacercariae
Diarrhea, Anorexia, Nausea,
Lethargy, Malaise, Seizures,
Fatigue, Abdominal pain.
Eggs in Feces,
ELISA.
Praziquantel,
Tetrachloroethylene,
Bithionol, Nicoflan,
Niclosamide,
Avoid eating
improperly cooked
food.Snail and Fish
Fascioloides
magna
Deer Intestine,
Liver
Egg → Miracidium
(Snail) → Cercariae →
Metacercariea
Anorexia, Weight loss,
Lethargy, Depression
Fecal examination, ELISA,
PCR, Necropsy
Tricabendazole,
Albendazole,
Rafoxanide.
Build watering points
on solid ground,
without Puddles.Snail

3. 3 | P a g e W w w . R C V e t S . c o m
Helminthology: Trematodes
Organism
Final Host Site of
Infection
Life Cycle
Symptoms/
Signs
Diagnosis Treatment Control
Intermediate
Opisthorchis
tenuicollis
Birds and
mammals.
Gallbladder,
Liver and
Biliary Tract
Eggs → (Snail) →
Miracidia → Sporocyst
→ Rediae → Cercariae
→ Metacercariae
Anemia,
Pancreatitis,
Pyogenic,
Cholangitis
Microscopic stool
examination,
ELISA,
FCB.
Praziquantel,
Surgery
Proper cooking of
fish,
Control intermediate
host
Snail
Gastrothylax
Cattle,
Buffalo,
Sheep, Goat
Rumen and
reticulum.
Eggs → Miracidia (Snail)
→ Cercariae →
Metacercariae
Diarrhea, Fever, Abdominal
Pain.
Fecal examination,
ELISA,
PCR
Thiabendazole
Praziquantel
Oxyclozanide
Medication,
Snail control
Snail
Gastrodiscus
Pig, Horse,
Man, Deer,
Monkey Large
Intestine
Eggs → Miracidia (Snail)
→ Rediae → Cercariae
(Aquatic Vegetation) →
Metacercariae
Diarrhea, Fever, Abdominal
Pain.
Fecal test to detect the
eggs.
Praziquantel
Tetrachloroethylene,
Mebendazole
Night soil should
never be used as a
Fertilizer,
Vegetables and meat
should be washed &
cooked properly.
Snail &
Aquatic
Vegetation
Schistosoma
(Blood Flukes)
Birds,
Mammals Blood
Eggs → Miracidia (Snail)
→ Sporocyst →
Cercariae
Skin Itches, Fever, Anemia,
Blood from Rectum and in
Urine, Hepatospleomegaly
Fecal Test, Blood Test,
Serology, PCR
Praziquantel Snail Control
Snail