Parasitism in livestock Flashcards
main parasites in ruminants
nematodes
trematodes
cestodes
main parasites in horses
large + small strongyles
ascarids
harmful effects of nematodes
clinical - diarrhoea, weight loss, death
sub-clinical - decr weight gain
harmful effects of nematodes - mechanisms of action
decr appetite
change in gut structure + function
immune + infl responses
harmful effects - haemonchus
sucks blood
harmful effects - strongylus
plug feeders
physical damage
verminous endarteritis
harmful effects - trematodes
acute - liver damage
chronic - blood + protein loss - albuminaemia
harmful effects in growing animals
decr weight gain
poor feed conversion ratio
+/- anaemia
death
harmful effects in adults
weight loss
+/- decr reproductive performance
decr milk/wool
spring - source of parasites
arrested larvae
coccidia - from older lambs
overwintered larvae
larvae from adults
spring - main parasite threats
nematodirus battus - lamb
ostertagiasis - calves
larval cyathostomins - foals
summer - main parasite threats
nematodes - calves, lambs, goats
parascaris - foals
cyathostmins - horses
autumn - main parasite threats
liver fluke - metacercariae in snails
nematodes - calves, lambs, goats
parascaris - foals
cyathostmins - horses
acute facioliasis
in autumn
from ingestion of millions of metacercariae
winter - main parasite threats
chronic facioliasis
control of endoparasites
limit exposure of susceptible animals to large no.s
anthelmintics to break parasite life-cycle
safe pasture
minimal no.s of susceptible animals
SCOPS guidelines - 8 steps
1- control strategy
2- quarantine to stops importation of resistant worms
3- test for anthelmintic resistance
4- administer anthelmintics effectively
5- use anthelmintics only when needed
6- select correct anthelmintics for the task
7- preserve susceptible worms on the farm
8- decr dependence on anthelmintics
The main nematode species causing disease (PGE) in British sheep are
Teladorsagia circumcincta Trichostrongylus spp. Nematodirus battus Haemonchus contortus Cooperia spp.
less important nematodes causing disease (PGE) in British sheep are
Nematodirus spp Oesophagostomum venulosum Chabertia ovina Bunostomum trigonocephalum Strongyloides papillosus
The main nematode species causing PGE in cattle is
Ostertagia ostertagi
less important nematodes causing disease (PGE) in cattle
Cooperia spp.
Trichostrongylus spp
Nematodirus helvetianus
horse worms
strongyles (“redworms”)
migratory and non-migratory
