Lice are a common winter issue
Small numbers often go unnoticed at first, but lice populations can multiply rapidly and spread through a mob within 24 hours.
If you notice sheep rubbing, scratching, or biting at their fleece, lice are often the cause. This irritation not only damages the fleece and pelt, but also disrupts grazing behaviour, which can negatively impact productivity and stock performance.
Lice-infested wool can become yellowed and matted, significantly reducing wool quality and value.
Best Practice for Lice Control
While shearing and sunlight help reduce lice numbers, they will not completely eliminate an infestation. Winter shearing provides an ideal opportunity to get on top of lice control before problems build through the colder months.
Off-Shears Treatment
Applying Unlock Pour On off shears, when using a snow or cover comb, provides rapid knockdown of existing lice along with long-term protection for up to 5 months.
Treating at this time helps:
- Prevent lice build-up over winter
- Keep sheep comfortable and productive
- Reduce fleece damage
- Carry protection through to lambing
- Minimise the risk of cross-contamination within the flock.
Using a snow or cover comb leaves enough wool fibre to retain the chemical effectively. If sheep are shorn too closely, it is best to wait 2–4 weeks before treatment to allow sufficient wool regrowth.
Jetting Race or Shower Dip Option
Alternatively, Unlock Concentrate can be applied through a jetting race or shower dip system.
For effective lice control:
Apply a minimum of 2.5L of dip wash per sheep
Ensure sheep are wet right through to the skin
Always read and follow label directions carefully
Treatment Options:
Unlock Pour On – 20L + 2.5L
Treats up to 555 adult sheep
Active ingredients: Deltamethrin & Diflubenzuron
Unlock Concentrate – 10L
At the lice treatment rate of 60ml per 100L:
Treats up to 6,666 adult sheep
Based on 2.5L application per head
Active ingredient: Diflubenzuron
If treating sheep more than 35 days off shears:
Use 150ml per 100L
Apply 3L per head due to extra wool growth
10L pack treats approximately 2,000 adult sheep
Resistance Management
As with all animal health treatments, it is good practice not to rely on the same chemical family year after year, as resistance can develop over time.
