Lecture 18 strongyles of ruminants Flashcards
what is the family and 2 genera of the strongyles of ruminants
family: chabertiidae
genera: chabertia and oesophagostomum
what are two features of chabertia and what are the hosts
bell shaped buccal capsule with NO teeth 1.5-2 cm tiny leaf crown holds onto chunks of mucosa- tissue feeder sheep, goats, cattle
where are chabertia located in the host
colon (LI)
what is the life cycle of chabertia
• L3 exsheaths in small intestine • enters mucosal glands • moults to L4 • L4 returns to lumen • migrates to large intestine • final moult in large intestine - NO EXTRA INTESTINAL MIGRATION
what is the PPP of chabertia
8 weeks
what is the species of chabertia and what effects does it have on the host
ovina
- feed on mucosa
- cause hemorrhage
- excess mucus production
- diarrhea
what climate will chabertia occur in
chabertia ovina will be in temperate areas
how many worms of chabertia ovina are pathogenic and what is the fecundity of female worms
200 are pathogenic and females lay 3000 eggs a day (high fecundity)
what is the common name for oesophagostomum
nodule worms- large nodules in the small intestine
what are the 4 species of oesophagostomum, what host do they occur in and where in the host
Oe. radiatum, cattle, cecum
Oe. columbianum, sheep, colon
Oe. venulosum, sheep, cecum
Oe. dentatum, pig, colon
what is the lifecycle of oesophagostomum
and what is the PPP
L3 migrates into glands in small &/or large intestine L4 emerges and migrates to large intestine
- PPP is 5-6 weeks
what are the features of Oe. radiatum and what is its common name
cylindrical buccal capsule small leaf crown (basically none) no external leaf crown cervical collar in 2 parts - common name- the nodule worm of cattle
what are 3 effects on the host of Oe. radiatum and what is the host
• susceptible (young) host, no reaction
• resistant animals, intense reaction
• nodule filled with eosinophils, larva killed, caseous lesion calcifies
“pimply gut”
• nodules cause Hb & plasma proteins to leak into gut
• interfere with gut motility
• anorexia, reduced weight gains
• adults cause diarrhoea
• strong immunity by 12 months of age- no reaction after this therefore low pathogenicity
- host is cattle
what is the effect on the host of Oe. dentatum and what is the host
- common parasite of pigs; more prevalent in northern states
- life cycle as for Oe. radiatum; nodules much smaller
- less pathogenic than Oe. radiatum
- can cause unthriftiness in pigs
what are the two oesophagostomum of sheep and which one is more pathogenic, where are they found geographically
Oe. columbianum (more pathogenic)- northern NSW and Queensland
Oe. venulosum- VIC
what is a strongyle of the pig that has the eggs passed in the urine
stephanurus dentatus- kidney worm of the pig
where are stephanurus dentatus worms found in the body of the host and what is the host
attached to the ureter or in the perirenal fat
pig
what is the distribution of the stephanurus dentatus
limited to warm, moist areas in Australia
tropical and subtropical areas worldwide
what is the lifecycle of stephanurus dentatus
• egg passed in urine****->L3 in 3-5 days • L3 ingested or can penetrate skin • migrate to liver via portal system (3 days) or aorta (8-40 days) • migrate in liver for 2-3 months • migrate to perirenal area • may migrate anywhere in body
what is the PPP of stephanurus dentatus
9 months
what is the pathogenesis of stephanurus dentatus
- migrating larvae can produce lesions, or abscesses anywhere in carcass
- liver migration causes elevation in liver enzyme concentrations (AST)- diagnostic
- affected pigs lose weight
- organs condemned at slaughter
what is the one important strongyle of birds
sygamus trachea- the gape worm
where is syngamus trachea located in the host and what is the host
located in the trachea in birds (poultry)
what are the features of syngamus trachea
cup shaped buccal capsule
up to 10 teeth
L1-L3 OCCUR IN THE EGG
and oh yeah…THE MALE AND FEMALE ARE ATTACHED- y-shaped, male is tiny
what is the lifecycle of syngamus trachea
- eggs coughed up and swallowed, passed in faeces
- 2 moults occur within egg (L1-L3 within the egg)
- egg or infective larvae (L3) may be ingested by birds, or slugs, snails and earthworms may act as
paratenic (no development) hosts - larvae penetrate intestinal wall and are carried in the blood via the liver to the lungs, then
break out into alveoli and migrate to trachea - prepatent period 2 weeks
what is the pathogenesis of syngamus trachea
- cause excess mucus production
- block airways
- respiratory distress - birds stand “gaping”
- blood feeders
how do you diagnose syngamus trachea
eggs (L1-L3) in feces
eggs are ellipsoidal and thin shelled with a thick operculum on both sides
