Cast your mind back to recent years, the relatively wet summers of 2021-23 led to high worm burdens in your livestock.

This summer we experienced a burst of early rain in December that may have reduced the effectiveness of an early summer drench.
Since then, it has been relatively hot and dry, and this may provide you a window of opportunity to give an effective, strategic summer drench.
Strategic summer drenching usually involves an effective drench at the beginning and end of summer. This is to take advantage of the destruction of worm larvae on pasture by heat and the lack of moisture.
The life cycle of the worm involves both your pasture and the animal. While the drench fixes the animal problem, the hot, dry conditions of summer will help eliminate the pasture problem.
Before doing so, it is worth establishing which, if any, parts of your flock require drenching.
Drenching is both expensive and time consuming therefore pre-drench faecal egg counts (FECs) will put some science and evidence into whether to drench.
Furthermore, worm resistance, particularly to the white and clear drenches, is common in Victoria. Unnecessary overuse and the incorrect use of drenches just add to the problem.
Ineffective chemicals and/or an inadequate drench procedure can reduce the effectiveness of summer drenching.
After drenching, try to put your sheep onto low-risk pastures. These may be paddocks previously grazed by cattle, cut for hay or silage, or grazed by low-risk sheep such as older wethers.
Ewes rearing lambs, and lambs after weaning are the most susceptible sheep in terms of worm burdens.
Large re-infestations of worms can occur in as little as three to six weeks if your drenching program is ineffective.
For further advice contact your local veterinarian or Agriculture Victoria veterinary or animal health officer.