Parasitism in livestock

Question 1

main parasites in ruminants

Answer 1

nematodes
trematodes
cestodes

Question 2

main parasites in horses

Answer 2

large + small strongyles

ascarids

Question 3

harmful effects of nematodes

Answer 3

clinical - diarrhoea, weight loss, death

sub-clinical - decr weight gain

Question 4

harmful effects of nematodes - mechanisms of action

Answer 4

decr appetite
change in gut structure + function
immune + infl responses

Question 5

harmful effects - haemonchus

Answer 5

sucks blood

Question 6

harmful effects - strongylus

Answer 6

plug feeders
physical damage
verminous endarteritis

Question 7

harmful effects - trematodes

Answer 7

acute - liver damage

chronic - blood + protein loss - albuminaemia

Question 8

harmful effects in growing animals

Answer 8

decr weight gain
poor feed conversion ratio
+/- anaemia
death

Question 9

harmful effects in adults

Answer 9

weight loss
+/- decr reproductive performance
decr milk/wool

Question 10

spring - source of parasites

Answer 10

arrested larvae
coccidia - from older lambs
overwintered larvae
larvae from adults

Question 11

spring - main parasite threats

Answer 11

nematodirus battus - lamb
ostertagiasis - calves
larval cyathostomins - foals

Question 12

summer - main parasite threats

Answer 12

nematodes - calves, lambs, goats
parascaris - foals
cyathostmins - horses

Question 13

autumn - main parasite threats

Answer 13

liver fluke - metacercariae in snails
nematodes - calves, lambs, goats
parascaris - foals
cyathostmins - horses

Question 14

acute facioliasis

Answer 14

in autumn

from ingestion of millions of metacercariae

Question 15

winter - main parasite threats

Answer 15

chronic facioliasis

Question 16

control of endoparasites

Answer 16

limit exposure of susceptible animals to large no.s
anthelmintics to break parasite life-cycle
safe pasture
minimal no.s of susceptible animals

Question 17

SCOPS guidelines - 8 steps

Answer 17

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

Question 18

The main nematode species causing disease (PGE) in British sheep are

Answer 18

Teladorsagia circumcincta
Trichostrongylus spp. 
Nematodirus battus 
Haemonchus contortus 
Cooperia spp.

Question 19

less important nematodes causing disease (PGE) in British sheep are

Answer 19

Nematodirus spp 
Oesophagostomum venulosum 
Chabertia ovina 
Bunostomum trigonocephalum 
Strongyloides papillosus

Question 20

The main nematode species causing PGE in cattle is

Answer 20

Ostertagia ostertagi

Question 21

less important nematodes causing disease (PGE) in cattle

Answer 21

Cooperia spp.
Trichostrongylus spp
Nematodirus helvetianus

Question 22

horse worms

Answer 22

strongyles (“redworms”)

migratory and non-migratory