Parasite Treatments

Question 1

What is an auto worm bolus?

Answer 1

A bolus that automatically releases anthelmintic every 3 weeks - prevents eggs release in the first place

Ivermectin auto worm boluses release wormer every 5 weeks to include the PPP

Question 2

How long do auto worm boluses last?

Answer 2

18 weeks

Question 3

What is a disadvantage of autoworm boluses?

Answer 3

Never develop immunity

Question 4

What is the best worming strategy?

Answer 4

Targeted worming
Based on faecal egg counts and growth rates

Worm calves with low growth rates and high faecal egg counts

Question 5

How can you control dictyocaulus viviparus in heifers in their first grazing season?

Answer 5

Huskvax
2 injections, 4 weeks apart, 2 weeks prior to turnout

+/- panacur in July - may prevent immunity

Question 6

How can you control telodorsagia circumsincta in sheep?

Answer 6

Use a long-acting anthelmintic eg: Cydectin after lambing but before turnout in the ewes
This prevents pasture contamination

Leave singles in refugia - less peri-parturient immune suppression

Question 7

How can you treat nematodirus battus in lambs?

Answer 7

Any anthelmintic but macrocyclic lactones = resistance

In April to June

Question 8

What are the 5 groups of anthelmintics?

Answer 8

1. Benzamidazoles - White
2. Imidathiazoles / tetrahydropyrimidines - yellow
3. Macrocyclic lactones
4. Amino-acetonitrile (Monapantel) - red
5. Spiroindoles (Derquantel and abamectin) - purple

Question 9

How can you treat nematodirus battus in lambs?

Answer 9

Any anthelmintic but macrocyclic lactones = resistance

In April to June

Question 10

What are the 5 groups of anthelmintics?

Answer 10

1. Benzamidazoles - White (fenbendazole)
   - no residual activity
   - kills developing larvae and adults
2. Imidathiazoles / tetrahydropyrimidines - yellow (levamisole)
   - no residual activity
3. Macrocyclic lactones (ivermectin or moxidectin)
   - ivermectin - residual activity 2 weeks
   - moxidectin - residual activity 3 weeks
4. Amino-acetonitrile (Monapantel) - red
5. Spiroindoles (Derquantel and abamectin) - purple

Question 11

How should you treat fasciola hepatica?

Answer 11

October - triclabendazole - kills juvenile stages
January/February - closantel - immatures and adults
April/May - Albendazole - removes all adults

Question 12

What additional flukicidal doses should be given on high risk farms?

Answer 12

2nd dose of triclabendazole in November

Triclabendazole in June when there is winter infection of snails

Question 13

Describe a suitable quarantine protocol to prevent worms.

Answer 13

Use class 4 (monapantel) or 5 (derquantel) anthelmintics and repeat in 3-6 weeks
Triclabendazole to treat fluke

Question 14

What worming strategy can you use for calves to be turned out in April to prevent PGE?

Answer 14

3 doses of a short acting anthelmintic, 3 weeks apart

Eg: fenbendazole

Question 15

What worming protocol would you recommend for calves turned out in May to protect against PGE?

Answer 15

2 doses of a short acting wormer, 3 weeks apart

Eg: fenbendazole

Question 16

What worming strategy can you use for calves to be turned out in April to prevent PGE?

Answer 16

3 doses of a short acting anthelmintic, 3 weeks apart

Eg: fenbendazole

Question 17

What worming protocol would you recommend for calves turned out in May to protect against PGE?

Answer 17

2 doses of a short acting wormer, 3 weeks apart

Eg: fenbendazole

Question 18

What flukicidal drugs MUST NOT be used in lactating dry cows? And when can they be used?

Answer 18

Triclabendazole, closantel, nitroxynil

Use in the 60day dry period

Question 19

What flukicidal drugs can be used in lactating dairy cows?

Answer 19

Albendazole, ricobendazole, oxyclonazide

Question 20

What is the only wormer with nil milk withhold?

Answer 20

Eprinomectin

Question 21

What combination products are available?

Answer 21

Levamisole + triclabendazole

Ivermectin + closantel

Question 22

When should you worm animals using a combination product?

Answer 22

At housing - dairy young stock and beef cattle

At drying off in Autumn - dairy cattle

Question 23

What can be used to treat psoroptes bovis?

severe scab formation along the back, shoulders and tail head

Answer 23

Permethrin

Resistance to macrocyclic lactones

Question 24

What flukicidal drugs are there?

Answer 24

Triclabendazole - all stages of fluke
- use at the beginning of the dry period in dairy cows = 48d WP

Closantel - kills late immature fluke (6-8w)

Nitroxynil - adulticide
Albendazole - adulticide (60 WP)

Question 25

What parasites should you consider in dairy calves being turned out for their first grazing season?

Answer 25

Ostertagia
Cooperia
Dictyocaulus viviparus
Fluke

Question 26

How can you prevent ostertagiosis using wormers?

Answer 26

Ivermectin used at 3, 8, 13 weeks after turn out

• PPP ostertagia - 3w
• ivermectin residual activity - 2w
• dose at 13w reduces the risk of type 2 disease

(Could use moxidectin with a residual activity of 3w)

Question 27

How can you prevent ostertagiosis for financially restricted farmers?

Answer 27

Benzamidazoles
- 3 and 6 weeks after turn out to prevent eggs being shed on to the pasture

Risk of type II ostertagiosis with this or protocol - give another dose when the cows are bought in

Question 28

What is a typical presentation of babesia divergens?

Answer 28

West of the UK
Yearling calves

Diarrhoea, haemoglobinuria, haemolytic anaemia, fever

Question 29

How can you diagnoses babesia in cattle?

Answer 29

Giemsa stained blood smear - meritzoites

Question 30

How can you treat bovine babesiosis?

Answer 30

Imidocarb
- very long meat withdrawal - 250 days!!
Need to inform the VMD

Blood transfusions

Expose young stock to infection
Only buy in from endemic areas or don’t buy in young calves (under 12m)
Synthetic pyrethroid pour on

Question 31

How can you manage neospora caninum?

Answer 31

Identify positive cows - serology
Cull positive cows - expensive
Breed positive cows to beef and sell calves

Dispose of all aborted material quickly and don’t allow dogs to scavenge
Good biosecurity
Don’t allow dogs to poo on feed

Question 32

How can a farmer control helminths in his adult milking cattle?

Answer 32

Macrocyclic lactone when bought in for housing

• eprinomectin (only one with no milk withdrawal)
• should have developed good immunity

Triclabendazole - at the start of the dry period
(48 day milk withdrawal)
- Albendazole (60h WP), oxyclozamide (72h WP)

Avoid wet pastures in Autumn

Dictyocaulus viviparus - annual boosters of huskvax and turn out 2 weeks later