Control of GI nematodes Flashcards
Give 5 examples of Helminth species that need to be controlled in cattle
- Ostertagia ostertagi
- Trichostrongylus spp
- Cooperia spp
- Fluke
- Dictyocaulus viviparus
Which drugs can be used to treat nematodes?
- Benzimidazoles
- Imidathiozoles
- Macrocytic lactones
Which drugs can be used to treat flukes?
Flukicides
- Triclabendazole
- Closantel
- Albendazole
What are the 5 R’s in to control helminths?
- Choose 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
- Administer the product in the Right way
A 120 cow dairy farm, grazes all cattle outside from May to October
• What species do you need to be aware of for milking cows, dry cows and late pregnant heifers?
- Ostertagia (disease would occur in august)
- Dictyocaulus (first season grazing calves)
- Fluke (October)
In March which parasite can be vaccinated against, when should this occur?
Dictyocaulus
- give before they are turned out, 2 doses, 4 weeks apart
A 120 cow dairy farm, grazes all cattle outside from May to October
• What treatment of the cattle should occur in may?
• What is the importance of this treatment?
GI nematodes
Ivermectin, 3,8,13 weeks after turnout. Preventing eggs shed onto pasture, prevents build-up of l3 in July. Overwintered L3, source of infection, die off by beginning of June.
In which month are fluke metacecariae on pasture?
September
What happens in October in the management of fluke?
House
- Diagnose – juvenile fluke antibody detection ELISA
- Treat – 2 weeks after housing could use triclabendazole (kills fluke from a week of age) or use FEC/Copro-ag test to diagnose and treat adult fluke approx. 8-10 weeks after housing (closantel/clorsulon)
Describe the control of the following parasites for Milking cows/dry cows:
- Ostertagia
- Dictyocaulus
- Fluke
- Probably dont need to do anything
- If lung worm controlled by vaccination/exposure in calves, then probably no action needed but can monitor exposure using ab detection ELISA with BMT
- Treating is complicated by the lack of suitable products.
A beef suckler herd that calves in Feb-March, houses cows in December, turns back out straight after calving
Describe the treatment needed for Dictyocaulus and GI nematodes (if any) and explain why
- Mothers immune to Dictyocaulus and GI nematodes
- Mothers will eat any overwintered L3 and their immune systems will kill them, so few eggs will be shed
- Calves probably suckling so eating very little grass, very low infection, if any
- No treatment necessary
A beef suckler herd that calves in Feb-March, houses cows in December, turns back out straight after calving
Describe the treatment needed for fluke (if any) and explain why
- No immunity builds up to fluke, dams and calves will be susceptible
- Over the winter, when cows are housed, can use FEC/Copro-ag to monitor infection in cows. Treat with adulticide if necessary.
- At the end of the grazing season, test the calves (serum antibody ELISA), treat 2 weeks after housing with TCBZ if positive, or wait until late winter and use FEC/Copro-ag test
Flock of 400 ewes, lamb in February, housed in December, turned out after lambing.
Triclabendazole resistance has been diagnosed on this farm, using a FECRT
- Describe how you would control fluke in this flock
- Sheep of all ages are highly susceptible to fluke, Acute disease can result in high levels of mortality.
- Spring (around lambing/before they go back out), test sheep using FEC, treat adults for parasites to prevent contaminating pasture.
- Autumn – if possible avoid wet/flukey pasture. Think about moving flock to dry ground/house early if necessary
- Winter at housing – can use Copro-ag test to check for infection and consider a second treatment if necessary – e.g. with nitroxynil
