TRICHOSTRONGYLE

Question 1

desc basic features of trichostrongyles

Answer 1

DIRECT
bursate
poorly dev buccal cav
cuticular decorations obvious
dx = excretory notch
females - ovijectors and vulval flap

Question 2

desc a basic tricostrongyle lifecycle

Answer 2

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

Question 3

name 3 nematode trichostrongyles found in the abomasum of ruminants

Answer 3

H. contortus
O. ostertagii
T. axei

Question 4

what is unusual about the bursa of haemonchus

Answer 4

2 x lateral lobes

1 x asymmetrical dorsal lobe

Question 5

how bit are ‘HOT’

Answer 5

H = 2-3cm
O = 1 cm
T = 0.5cm

Question 6

why is haemonchus known as the barbers pole

Answer 6

entwined uterus and blood filled GI of the female

Question 7

what 3 trichostrongyle nematodes are found in the SI?

Answer 7

Nematodirus
Tricostrongyle spp
Cooperia

Question 8

what 3 tricho nematodes are found in the LI

Answer 8

C- chabertia
O- oesophagstomum
T- (trichuris - THIS IS WHIP WORM, not tricho)

Question 9

what is a dx morph feature of cooperia

Answer 9

watch-spring coil
cephalic (AND cervical) vesicle
stumpy spicules

Question 10

how large are trichostrongyle eggs and whats do they look like

Answer 10

70-90um (except nematodirus battus = 150! and h.contortus)

in poo = undiff; wi 24hrs = larvated

Question 11

how might you describe a nemadirus infestation

Answer 11

cotton-wool,

1cm long

Question 12

unlike haemonchus/cooperia with short stumpy spicules, what trciho has a very long and thin one?

Answer 12

nematodirus

Question 13

what disease does nematodirus cause, and what environmental conditions are required

Answer 13

• watery, explosive d+ at 6wo lambs in may-jute

- prolonged cold pasture then 10degree rise = mass emergence of overwintered iL3

Question 14

how can nematodirus be controlled since it is resistant to MLs

Answer 14

grazing management and dz forecasting - not putting grazing lambs out when immune naive
props tx april/june of mum

Question 15

what tricho is found in the trachea and the only nematode that will be found there

Answer 15

dictylocaulus viviparous

Question 16

how do you desc the buccal capsule of chabertia

Answer 16

bell-shaped, looks more like strongylus

Question 17

what distinctive feature does nematodirus have at the cr end>

Answer 17

both bubble cephalic vesicle and cervical vescicles

Question 18

which dictylocaulus app has a cephalic button>

Answer 18

d. filiaria (sheep and goats)

Question 19

what are the differences in lifecycle of dictylocaulus and other tricho>

Answer 19

retains ALL cuticles
L1 don’t need to feed as have food granules in them
3 phases: pre-patent, patent, post-patent

Question 20

describe the phases of dz from dictylocaulus

Answer 20

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.

Question 21

how are dictylocaulus spread from poo

Answer 21

pilobomus fungi grow from poo, larvae climb up and when fruiting bodies pop- off so do the iL3

Question 22

when is haemonchus contorts infection usually seen?

Answer 22

late summer

Question 23

what lung worm (dictylocaulus app) causes rest dz in horses but not donkeys>

Answer 23

d. arfiedli

Question 24

what is meullerius capillaris

Answer 24

a lung worm, trichostrogyle, of the sheep - it is NON-pathogeneic

Question 25

what is husk?

Answer 25

dz caused by d. viviparous in cattle, hence name of vaccine = husk vac

Question 26

what trichostrongyle has a buccal lancet?

Answer 26

h. contortus

Question 27

what are the signs of h. contorts infection?

Answer 27

kg loss, oedema and anaemia

Question 28

how much blood does haemonchus drink>

Answer 28

0.1ml/worm/d

Question 29

how does ostertagia and telodorsagia cause disease>

Answer 29

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.

Question 30

there are 2 types of ostertagiosis, descr both

Answer 30

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

Question 31

when does telodorsagiosis occur

Answer 31

august

4-12wo lambs

Question 32

what climate is nematodirus batus adapted too?

Answer 32

cold - norway etc