Tips for Drench Resistance - Worm Management

Worm management

The 4 key principles of worm management everywhere:

1. Do regular worm egg counts

2. Know your drench resistance status

3. Maximise non-chemical worm management

4. Seek professional advice

What Causes Drench Resistance?

• Drench resistance is caused by exposing worms to several treatments of same drug
• This can kill susceptible worms but leaves increasing numbers of resistant worms
• The resistant worms are genetically different to susceptible worms
• Resistant worms pass on their resistance to future worm generations
• The practice of drenching sheep onto clean pastures with drenches that are not 100% effective leads to the rapid development of resistant worm populations.

How Quickly Can Drench Resistance Develop?

The rate of development of drench resistance is influenced by factors including:

• The chemical group and persistency of the product involved
• The frequency of treatments
• The timing of treatments
• The worm species involved
• Environmental factors

 ·         The earlier you detect resistance, the EASIER IT IS TO MANAGE

·         UNNECESSARY DRENCHING is the major cause of drench resistance

There are several effective non-chemical ways to control worms.

Some management tools are:

• Cross-Grazing with Cattle;
• Buying Rams from studs that breed sheep resistant to worms;
• Using “Smart Grazing”;
• Managing Nutrition to help sheep develop resistance to worms.