TRICHOSTRONGYLE Flashcards
desc basic features of trichostrongyles
DIRECT bursate poorly dev buccal cav cuticular decorations obvious dx = excretory notch females - ovijectors and vulval flap
desc a basic tricostrongyle lifecycle
eggs laid in faeces L1 develops and hatches feeds on bacteria in faecal pat L3 is ensheathed but retains L2 coat iL3 on grass ingested burrows in to GI mucosa (site is dx of spp) --> black scour
name 3 nematode trichostrongyles found in the abomasum of ruminants
H. contortus
O. ostertagii
T. axei
what is unusual about the bursa of haemonchus
2 x lateral lobes
1 x asymmetrical dorsal lobe
how bit are ‘HOT’
H = 2-3cm O = 1 cm T = 0.5cm
why is haemonchus known as the barbers pole
entwined uterus and blood filled GI of the female
what 3 trichostrongyle nematodes are found in the SI?
Nematodirus
Tricostrongyle spp
Cooperia
what 3 tricho nematodes are found in the LI
C- chabertia
O- oesophagstomum
T- (trichuris - THIS IS WHIP WORM, not tricho)
what is a dx morph feature of cooperia
watch-spring coil
cephalic (AND cervical) vesicle
stumpy spicules
how large are trichostrongyle eggs and whats do they look like
70-90um (except nematodirus battus = 150! and h.contortus)
in poo = undiff; wi 24hrs = larvated
how might you describe a nemadirus infestation
cotton-wool,
1cm long
unlike haemonchus/cooperia with short stumpy spicules, what trciho has a very long and thin one?
nematodirus
what disease does nematodirus cause, and what environmental conditions are required
- watery, explosive d+ at 6wo lambs in may-jute
- prolonged cold pasture then 10degree rise = mass emergence of overwintered iL3
how can nematodirus be controlled since it is resistant to MLs
grazing management and dz forecasting - not putting grazing lambs out when immune naive
props tx april/june of mum
what tricho is found in the trachea and the only nematode that will be found there
dictylocaulus viviparous
how do you desc the buccal capsule of chabertia
bell-shaped, looks more like strongylus
what distinctive feature does nematodirus have at the cr end>
both bubble cephalic vesicle and cervical vescicles
which dictylocaulus app has a cephalic button>
d. filiaria (sheep and goats)
what are the differences in lifecycle of dictylocaulus and other tricho>
retains ALL cuticles
L1 don’t need to feed as have food granules in them
3 phases: pre-patent, patent, post-patent
describe the phases of dz from dictylocaulus
penetration phase - ingestion to lymph-trach migration
pre-patent- imflm response in lung in response to L4
patent- response to L5 migrating from bronchi - trachea = emphysema, hypoxia, gasping, death pos
post-patent - immunogenic so good immune, resolution and epitheliasagtion of lung tissue.
how are dictylocaulus spread from poo
pilobomus fungi grow from poo, larvae climb up and when fruiting bodies pop- off so do the iL3
when is haemonchus contorts infection usually seen?
late summer
what lung worm (dictylocaulus app) causes rest dz in horses but not donkeys>
d. arfiedli
what is meullerius capillaris
a lung worm, trichostrogyle, of the sheep - it is NON-pathogeneic
what is husk?
dz caused by d. viviparous in cattle, hence name of vaccine = husk vac
what trichostrongyle has a buccal lancet?
h. contortus
what are the signs of h. contorts infection?
kg loss, oedema and anaemia
how much blood does haemonchus drink>
0.1ml/worm/d
how does ostertagia and telodorsagia cause disease>
L4 develop in gastric gland and prevents HCl production
inc pH means pepsinogen doesnt convert to pepsin = protein not degradeed
epi cells of the GIT try to replace parietal cells, but tight jct suck and so it leaks plasma proteins into the GIT
osmotic potential = water influx.
there are 2 types of ostertagiosis, descr both
type 1 = august
- heifers, 1st year
- ing large numb of overwintered iL3
- PPP = 3wks
type 2 = spring
- yearling ingest hypobiosed iL3, which emerge synchronously as L5
- v high mortality
when does telodorsagiosis occur
august
4-12wo lambs
what climate is nematodirus batus adapted too?
cold - norway etc
