2. Flukes. rumen flukes, lancet flukes Flashcards
Geographical presence of paramphistomatidosis
- worldwide in grazing domestic and wild ruminants
- especially in tropic and subtropical climate areas
Paramphistomatidosis is caused by __ ?
Paramphistomum ichikawai
P. leydeni
P. cervi
Calicophoron (= Paramphistomum ) daubneyi - predominant rumen fluke species in Europe
C. microbothriodes
C. microbothrium
Approximate size of rumen flukes
- 6-12 mm long, 2-4 mm wide
- pink/reddish, conical
- small sucker on the oral end and bigger one on the opposite end
- tough body is filled with genitalia and two branches of intestinal caeci
Life cycle of rumen fluke
- indirect, similar to liver flukes but intermediate host may be other than Lymnaea snails and juvenile flukes never leave the intestinal canal during their route from small intestine to the forestomach
- intermediate hosts: freshwater or amphibious snails: Bulinus spp, Lymnaea spp
- MI -> SPO -> RE -> CE
Process of infection by rumen flukes
- infection per os with metacercariae
- immatures (1-3 mm) -> duodenum, abomasum (ca 4-6 weeks) -> rumen, reticulum
How long is PP period for rumen flukes?
- 3-4 months
- 40-50 days in lambs
Pathogenesis and clinical signs of rumen fluke disease
Pathogenesis:
Inflammation, local haemorrhages, necrosis
Clinical signs:
Acute (intestinal) paramphistomatidosis:
- due to migration of young flukes in the duodenum for 4-6 weeks: profuse diarrhea, anorexia, intense thirst, rectal haemorrhage followed by straining anemia, edema (due to hypoalbuminaemia, emaciation, death (up to 90%), mainly in lambs and young cattle in warm regions
Chronic (rumen) paramphistomatidosis:
no symptoms
Diagnosis of paramphistomatidosis
Acute form:
- no eggs, juvenile flukes in faeces (washing of faeces through sieve)
- necropsy
Chronic form:
- detection of the eggs (colour !) - like F. hepatica but colourless, a bit larger and more resistant
- necropsy
Treatment of paramphistomosis
Acute form:
- stop grazing on infected pasture
- e.g. niclosamide/albendazole 15-20 mg/bwkg (partial effect for immatures)
Chronic form:
- e.g. oxyclozanide 15 mg/bwkg, closantel 10 mg/bwkg
Dicrocoeliosis — ?
Lanceolat fluke/ Small liver fluke disease
Schistosomatidosis - blood fluke disease
Geography
Tropical and subtropical zones
Low veterinary importance
Very high public health importance
Caused by
Schistosoma bovis - portal and mesenteric vein
Schistosoma mattheei - intestinal, hepatic and bladder veins
Schistosoma japonicum - portal and mesenteric vein
Schistosoma mansoni - intestinal schistosomosis
Schistososma haematobium - urinary or bladder schistosomosis
Morphology of Schistosoma
Adults:
- 0,5-3 cm long
- thread-like shape
- sexual dimorphism: male - broad and flat, inwardly curves forming a groove; female - thin, shred-like, slightly longer
Life cycle of Schistosoma
Indirect with freshwater snails
PP period of Schistosoma
30-40 days
Paramphistomatidosis (Paramphistomosis) — ?
Rumen fluke disease
Site of rumen Paramphistomum/Calicophoron
Rumen, reticulum
Dicrocoeliosis is caused by ___ ?
- Dicrocoelium dendriticum (syn. D. Lanceolatum) - lancet/small liver fluke
- Dicrocoelium hospes in tropical regions
Morphology of adult lancet fluke
- 8-12 mm
- transparent body is whitish and brown string of eggs shows through the tissue
- small sucker on the tip of the head and another one lay close to it in ventral side
- inner part of the body is filled with large mass of well developed genitals
- 2 branches of intestinal caeci are not functional => not visible
- lancet-shaped, integumentary without spines
Life cycle of lancet fluke
- 2 intermediate hosts!!!
- 1st host: terrestrial snail
- 2nd host: ants
- Adult worms produce small (40-48 micrometers) eggswhich are shed with feces and contain miracidium
- The miracidium is able to hatch if the egg is consumed by a landsnail
- Larva hatches in the intestine of snail and develops in the body cavity of the intermediate host to sporocyst
- The bladder-like sporocyst produces several generations of other sporocysts (daughter sporocysts)
- After some time, inside the sporocyst, cercariae develop (omitting the redia stage) by asexual budding, called paedogenesis. Cercariae have very long tails and a sharp spine on the tip of the head, called stylet
- Cercariae are not able to swarm out of the snail spontaneously but leave it in the expelled mucus of snail while the mollusk crawls on the plants. The cercariae remain is in slime balls attached to surface.
- Ants ingest the sticky slime and this way they are infected with the larval lancet fluke. After penetration of the intestine with their stylet the larvae turn to metacercariae: many of then form a thick walled cyst in the body cavity but only one of them goes to the side of sub-oesophageal ganglion and modify the behaviour of the ant. Infected specimens of ant grab the top of the grass and remain motionless.
- Ants are accidentally ingested by grazing animals. Encapsulated metacercariae can get out of their own capsule in the small intestine of final host and turn to juvenile flukes
- Emerging juvenile flukes reach the liver through the biliary ducts and develop to adults.
Intermediate hosts of rumen flukes
In Europe its mainly
- Galba truncatula for Calicophoron
- planorbids for Paramphistomum
Planorbid snails live longer than Lymnaea snails and able to survive without water for rather long period
