sheep nematode

abomasum worm nematode

Ostertagia circumcincta

Haemonchus contortus

Trichostrongylus axei

SI worm nematode

trichostrongylus vitrines

Tricostrongylus colubriformis

Nematodirus battus (L3 in egg ingested)

braod categories of nematode

gut worm-

haemonchus

nematodirus

lungworms

what nematode egg can be differentiated at FWEC

nematodirus egg. bigger than other strongyle egg.

nematode species cannot be differentiated via FWEC

describe life cycle of GI nematode eg trichstorngylus

name one exception

2week to 3m cycle

1. sheep pass egg in dung

2. L1 release from egg. live in farces feeding on bacteria

3. L1—>L2. feed on bacteria

4. L2—>L3. infetcive stage

5. L3 migrate to pasture in suitable warm and wet weather (killed by UV)

• L3 retain L2 shell. more durable than L1 and L2.

• warmer—> energy researve use up faster—> come out of shell

6. L3 eaten by new host→ wall of stomach or intestine

7. develop into L4 (14d)—> lay eggs

• adult viable for several months

• prepatent period (ingestion—> egg laying)

exceptions: Ostertagia circumcinta, nematodirus battus, hemonchus contortus, lungworm. (see cattle)

prepatent period: ingestion of L3 to detectable in faeces

16-21 days

common way to do FWEC and interpretation

pooled sample

<250: low, no tx needed

250-750: moderate, tx mayhelp

>750: high, tx reccomended

teladoesagia circumcincta

aka ostertagia circumcincta— brown stomach worm

most common PGE species, part of mixed infection

• type II ostertagiosis— affect store/ replacement ewe lamb

hypobiosis(encyst) in gastric galnd over winter

Nematodirus battus— name key species difference of life cycle

LONG 8-9m cycle

• L1—>L2—>L3 in the egg and do not moult: egg over winter

• slow life cycle: nematodirus pause development in winter

• weather trigger L3 hatching

  • cold snap <10C followed by 10-17C. usually apr- jun/ autumn if not exposed in spring

nematodirus battus mainly affect what group? what cs would you see

severe outbreak in lamb 6-12week old

adult should have good immune response

• inappetnece, dehydration, abdo pain, acute scour, sudden death

• seeen at 6-12week old and right time of year: apr-jun, autumn