Keeping your flock safe

Quarantining all incoming sheep is crucial to minimise the risk of introducing resistant worms onto your farm and into your flock.

The quarantine process involves keeping all incoming sheep isolated and giving appropriate treatments before you let them graze and mix with the resident flock. This includes replacement ewes bought in from other flocks, rams bought in for tupping and even your own flock returning after grazing elsewhere.

Assume all incoming sheep are carrying resistant roundworm infections and use appropriate treatments. Using more than one wormer reduces the chance of any resistant worms surviving treatment.

The SCOPS Gold standard treatment advice is to use both the newest anthelmintic groups - Group 4AD (orange) and Group 5SI (purple). The Silver standard is to use one of the newest anthelmintic groups along with a Group 3ML (clear). The Bronze standard is to only use one of the newest anthelmintic groups.

Using the Gold standard advice offers the most efficient and effective approach to ensuring all resistant worms are targeted and removed.

If there is a high risk of sheep scab, the Gold standard involves treating all incoming sheep with an organophosphate (OP) plunge dip. OP dips must be used responsibly and the user must hold a Certificate of Competence.

Contract mobile dippers can be used if you don't have the correct facilities or certification. OP dips are not authorised to be used in showers, jetters or sprayers and should only be used in a plunge dip.

The Silver standard is to use a Group 3ML moxidectin injectable and the Bronze standard is to use a Group 3ML doramectin injectable.

The table shows the SCOPS recommendations for effective quarantine dosing.

Gold standard   Silver standard   Bronze standard

4-AD = Monepantel (ZolvixTM)
5-SI = Derquantel/abamectin (StartectTM)
Mox (inj) = Moxidectin injection*
Do = Doramectin (DectomaxTM)
OP = Organophosphate plunge dipMox (oral) = Moxidectin oral drench

Another important parasite to be cautious of bringing onto your farm is liver fluke. Sheep can be tested for liver fluke antibodies on arrival but if the incoming sheep are coming from a high fluke area, they should also be treated with the appropriate flukicide.

This may involve treating with a triclabendazole drench during quarantine and then treating again six to eight weeks later with closantel to target any remaining adult fluke.

Keeping sheep on hard standing for 24 to 48 hours on arrival minimises the risk of resistant eggs passing onto the pasture and allows time for necessary quarantine treatments to do their job. It also allows time to observe the newcomers for any other signs of disease.

After the necessary treatments and testing, sheep can be turned out to grazing but still need to be isolated from the resident flock for a minimum of three to four weeks.

The grazing should have been grazed already by the resident flock, so any worms carrying resistance genes that could have survived the quarantine treatment are diluted with susceptible worms.

Then use a faecal egg count to ensure the quarantine anthelmintics have been effective. If results show the appropriate quarantine treatments have worked and other factors such as sheep scab and the risk of liver fluke have been assessed, the sheep can then be introduced to the resident flock.

Your local Registered Animal Medicines Advisor will be able to work with you to advise the best quarantine strategy for your individual flock.

For more information on effective quarantine protocols speak to one of our Registered Animal Medicines Advisors in-store today.