Sustainable control of parasites

Question 1

What are the main GI nematodes in sheep?

Answer 1

Teladorsagia circumcinta
Haemonchus contortus
Nematodirus battus

Question 2

Do the main GI nematodes in sheep have direct or indirect life cycles?

Answer 2

Indirect

Question 3

When does infection with teladorsagia usually occur?

Answer 3

First season lambs in late summer/autumn

Question 4

How are nematodirus battus transmitted?

Answer 4

From lambs the previous year

Question 5

When does infection with nematodirus usually occur?

Answer 5

A cold snap followed by temps above 10 C

Question 6

What is the main mode of transmission of haemonchus contortus?

Answer 6

Hypobiosis and reemergence in ewes

Question 7

What does in refugia mean?

Answer 7

leaving at least some of the parasite population unexposed to
anthelmintics

Question 8

What are the 3 methods of anthelmintic control?

Answer 8

Prevention - chemoprophylaxis, treat all animals at start of grazing season
Evasion - dose and move
Dilution - decrease effective density of susceptible animals

Question 9

What are some modifications of rotational grazing?

Answer 9

Creep grazing - young animals get clean pasture

Hoover effect - resistant adults on field first

Question 10

How do you detect resistance?

Answer 10

Faecal egg count reduction test

Question 11

What is the best method of treatment that wont cause resistance?

Answer 11

Targeted selective treatment - choose individual animals to treat

Question 12

How do you detect the animals which have a high worm burden?

Answer 12

Faecal egg count Diarrhoea/dag score

Body condition

Question 13

What is the intermediate host of fasciola hepatica?

Answer 13

Snail

Question 14

What flukicide can be used to kill very young fluke/treat acute disease?

Answer 14

Triclabendazole

Question 15

What flukicides will kill older fluke?

Answer 15

Nitroxynil

Closantel

Question 16

What are the main GI nematodes in horses?

Answer 16

Cyathostomins
Strongyles
Parascaris equorum
Anoplocephala perfoliata

Question 17

How do cyathostomins cause disease?

Answer 17

Encyst for >3 years

Mass emergence causing colitis

Question 18

How does strongyles cause disease?

Answer 18

Clocks cranial mesenteric artery - arteritis

Question 19

How does parascaris equorum cause disease and what does it affect?

Answer 19

Most significant in foals - blocks intestine

Question 20

How can you diagnose nematodes in horses?

Answer 20

Faecal egg counts
Cyathostomin ELISA
Post mortem

Question 21

When should you treat horses for nematodes?

Answer 21

200epg as a cut off from faecal egg count

Question 22

What can you use praziquantel to treat?

Answer 22

Tapeworms - anoplocephala perfoliata

Question 23

What drugs can treat a wide range of nematodes?

Answer 23

Ivermectin
Moxidectin
Pyrantel
BZ - Fenbendazole

Question 24

How do you do a faecal egg count reduction test?

Answer 24

Do FEC
DOse
Do faecal worm egg count 14 days after

Question 25

When is there resistance?

Answer 25

<90% result when difference divided by starting FEC

Question 26

What are cyathostomins resistant to?

Answer 26

Benzimidazoles eg. fenbendazole

Pyrantel

Question 27

What is parascaris equorum resistant to?

Answer 27

Macrocyclic lactone - ivermectin and moxidectin

Question 28

What is the immunity like in cyathostomins, strongyles and parascaris?

Answer 28

Bad/incomplete in cyathostomins, strongyles

Good in parascaris

Question 29

What methods of treatment can be used? Do they cause resistance?

Answer 29

Fixed interval dosing - causes resistance
Only when disease is proven - no but not regular so resurgence
Target dosing in responce to positive worm egg count - no, best method