Control of Cattle Helminths

Question 1

What helminth species need to be controlled in cattle?

Answer 1

Oestertagia ostertagi

Trichostronylus spp

Cooperia spp

Fluke

Dictyocaulus viviparus

Question 2

What are the 5 ‘r’s?

Answer 2

Chose the right product for the type of worm

Treat the right group of animals

Treat at the right time of year

Treat using the right dose rate

Administer the product in the right way

Question 3

What should control programmes integrate?

Answer 3

Drug control programmes

Managment strategies

Vaccination (for D.viviparus)

Question 4

What drug classes are used against Nematodes?

Answer 4

1 BZs- white drenches- albendazole

2- LEV- Imidathiazoles tetrahydropyrimidines- yellow drenches- levamisole

3MLs- clear drenches- ivermectin

Question 5

What drugs are used as flukicides?

Answer 5

Triclabendazole

Closantel

Albendazole

Oxyclosanide

Question 6

120 cow dairy farm, grazes all cattle outside from may to october

What constraints do you nedd to be aware of for milking cows and dry cows?

Answer 6

Milking/Dry Cows

• Ostertagia- probably don’t need to do anything
• Dictyocaulus- if lung worm controlled by vaccination/exposure then no action needed but can monitor exposure using Ab dectection
• Fluke- treating milking and dry cows is complicated by the lack of suitable products. Complex diagnosis FEC/ag tests, can use some TCBZ at drying off (50 day milk withhold), albendazole and oxyclozanide (60 and 108 hours)
• No flukicide has any residual activity- can reduce milk yield by 15%
• Challenge is seasonal- high risk in autumn

Question 7

120 cow dairy farm, grazes all cattle outside from May to October

What parasites should you be aware of and how should they be controled?

Answer 7

Ostertagia, Dictyocaulus, Fluke

• March before turnout vaccinate against Dicto
• May- GIN, ivermectin, 3,8,13 weeks after turnout. Preventing eggs sheding onto pasture, and build of of L3 in July, Overwintered L3, source of infection, die off by beggining of June
• Or Monitor FEC and DLWG monthly and treat when FEC >200epg
• Pasture managment- avoid pasture used last year until late June
• Hypobiosed larvae- dose at housing/winter to kill hypobiosed L4
• Fluke- metacercariae on pasture in september
• House- October- diagnose juvenile fluke antibody detection, treat 2 weeks after housing- triclabendazole, or treat 8-10 weeks with FEC and closantel

Question 8

400 ewes, lamb in February, housed in December, turned out after lambing

Triclabendazole resistance has been diagnosed on this farm

How should fluke be controlled?

Answer 8

Sheep don’t acquire immunity from Fluke- all ages susceptible

Spring- around lambing/before turnout FEC and ag test to see if ewes are infected, if infected treat with adulticide to prevent egg contmainatino

Summer- Plan grazing for autumn

Autumn- Avoid wet flukey pasture, check fluke forecasts- decide whether leave move inside. From September onwards use monthly blood tests to measure appearence of antibodies in lambs- treat infections with closantel

Winter- use copro-ag test to check for infection, consider second treatment if necessary- Nitroxynil