Controlling worms

Australian woolgrowers spend 10% of their annual wool production on worm control. Worm infestations in sheep can lead to a loss of condition and even death. While there is a range of effective products available to control worms in your sheep, the threat of drench resistance means that you need to choose products carefully.

Drench resistance is the acquired ability of a worm to survive in the presence of normally lethal levels of a drench. Originally resistant worms are rare in a population but a genetic mutation allows them to survive the drench and then pass on their resistant genes to their offspring.

Drench resistance represents a major problem facing the Australian sheep industry. With no new actives on the horizon and resistance to the major drench families growing steadily across the country, producers need to explore new techniques to ensure sustainable worm control.

Drench resistance can triple your worm control costs because of less effective control, the need for additional testing and drenching, and losses in sheep with heavy worm burdens.

While resistance is developing, producers may be experiencing significant subclinical production losses that are not easily seen. One of the challenges growers face is to equate these losses with developing resistance.