3 Dicrocoeliosis of ruminants (Family Dicrocoelidae: Dicrocoelium, Eurytrema, Platynosomum) Flashcards
Dicrocoeliidae
General Morphology
- Size: 6-10mm
- Attachment organs: os + acet, anterior end, well developed
- Genital pore: anterior to acet.
- Ovary: posterior to testes
- Testes: Oblique position
Dicrocoelium dendriticum
IH
Has 2 IH
1. Land snail
2. Ant
Dicrocoelium dendriticum
FH
Ruminants (Sheep most often)
Horse
Rabbit
Camels
Man
Dicrocoelium dendriticum
Location
Adult: Bile ducts, gall bladder, pancreas
Juvenile: small bile ducts
Dicrocoelium dendriticum
Eggs
- Small
- Oval
- 2x thin shells w/operculum
- Embryonated with Miracidium
- Dark brown
Dicrocoelium dendriticum
Morphology
Compared to F. hepatica
* Slender
* More transparent
* Smaller
Dicrocoelium dendriticum
LC
- Embryonated eggs pass with feces into environment
- Egg is ingested by land snail and Miracidium hatches in the intestine
- Miracidium penetrated the gut wall and becomes Sporocyst
- Sporocyst produces daughter sporocysts which develope Cercaria
- Cercaria leave the daughter sporocyst and accumulate in mantle where mucus is secreated from
- Cercaria are enceloped in a slime formina a slime ball, that are deposited on vegetation
- Slime balls are eaten by Ants (2nd IH) and Metaceercaria encyst in the body cavity
- Few of the cercaria will migrate to subesophageal ganglion and encyst there - altering the ants behaviour
- When temperature in the evening drops, infected ants climb to the tips of grasses and hang there by their madibles
- FH can more easily ingest them.
- In FH: excyst in the intestine and migrate up to bile ducts via ductus choledochus (no liver migration)
Dicrocoelium dendriticum
Epidemiology
- IH do not need moist environment
- Eggs can survive up to 1 year on dry pasture
- Infection of snails and ants occur in summer, autum, spring
- Peak risk for FH in spring, but occurs whole grazing season
Dicrocoelium dendriticum
Pathogenesis
- Enlargement of bilary duct
- Cirrhosis and hypertrophy of biliary epithelium
Dicrocoelium dendriticum
Clinical signs
Only observed when there is large number
* Anemia
* Emaciation
* Decreased production (wool, milk)
Dicrocoelium dendriticum
Diagnosis
- Fecal examination - Sedimentation
Dicrocoelium dendriticum
Treatment
Administrated Orally
* Albendazole (2x 15mg/kg)
* Fenbendazole (5x 20mg/kg)
* Netobimin (20mg/kg Cattle)
* Praziquantel (50mg/kg)
Dicrocoelium dendriticum
Prevention
- Molluscicide - reduce snail population
- Keeping pasture free of debris (bords, burlap bags)
Eurytrema
Main species
- Eurytrema pancreaticum
- Eurytrema coelomaticum
Eurytrema pancreaticum
IH
Has 2 IH
1. Land snail - Bradybaena
2. Grasshopper - Conocephalus sp.
Eurytrema pancreaticum
FH
Ruminants
Herbivores in general
Eurytrema pancreaticum
Location
- Pancreas, bile ducts, duodenum
Eurytrema pancreaticum
Morphology
Size: 10-18mm
Shape: Broad and oval
Attachment organs: They are large and os is larger than acet.
Eurytrema pancreaticum
LC
- Embryonated eggs are released with feces into environment
- Egg is ingested by snail
- In IH: Miracidium to Sporpcyst to Cercaria
- Cercaria enters environment (before dawn)
- Cercaria is ingeted by grasshopper - become Metacercaria
- Infective Metacercaria released into environment
Humans infected by eating salad
Eurytrema pancreaticum
Pathogenesis
- Inflammation of pancreatic ducts, visible when opened (necropsy)
- Fibrosis and atrophy of pancreas
Eurytrema pancreaticum
Clinical signs
Anorexia
Eurytrema pancreaticum
Treatment
Praziquantel
Eurytrema pancreaticum
Diagnosis
Sedimentation method (fecal sample)
Platynosomum fastosum
Morphology
Size: Small 4-8mm
Similar to D. dendriticum except Testes are horizontal (side by side) not tandem
