Making More from Sheep Australian Wool Innovation Limited Meat & Livestock Australia
MODULE 11: Healthy and Contented Sheep
Tool 11.15
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Quarantine may need to be adopted if sheep are agisted or travel along roads where exposure to other sheep is possible. Quarantine if stray sheep are mixed with your own sheep.

Drench resistance

Drench resistance is widespread. Always drench introduced sheep with 3-4 chemically unrelated actives, e.g. a macrocyclic lactone (ML), white benzimidazole and clear levamisole drench combination. Also consider using naphthatophos or closantel in regions with barber’s pole worm. Drench check all new sheep 10 days post drenching to ensure the drench is effective.


The footrot bacterium Dichelobacter nodosus survives off sheep for up to 7 days. Keep newly introduced sheep in quarantine and ensure resident sheep do not walk across the same ground for at least 7 days. At least 3 months of lush pasture growth is necessary to allow expression of footrot. Release new sheep from quarantine only after their feet are closely inspected. Seek advice if you have no experience of footrot. Note that in drought conditions, quarantine should extend until the next lush pasture growth period. Some evidence indicates that cattle may act as carriers of footrot for short periods in wet conditions. Quarantine new cattle for at least a few weeks if you are not sure of their previous exposure to sheep.

Ovine Johne's disease (OJD)

Given the very slow nature of OJD development, no quarantine will guarantee freedom. Use other strategies, such as buying low-risk sheep.

Liver fluke

Drench all new sheep with triclabendazole on arrival if they come from a liver fluke area, unless you are certain of fluke status. Check fluke egg counts 8 weeks later to ensure the drench is effective as some fluke drench resistance is emerging.


Over 30% of flocks have lice, so the risk of buying lice with sheep of uncertain origin is high. It may take up to 18 months for low levels of lice to become evident. Contact NSW DPI for details of the new lice detection test (Tool 11.13). In some circumstances, lice can survive off sheep for up to 21 days (normally less), so always put new sheep through handling facilities last, including at shearing.