What is used to treat sheep for lice? - briefly
Topical insecticides—commonly pyrethrin‑based sprays or pour‑on preparations containing ivermectin or moxidectin—are applied to eliminate lice on sheep. Dosage follows label recommendations to ensure effective control and animal safety.
What is used to treat sheep for lice? - in detail
Effective control of ovine lice relies on a limited set of pharmacological agents and complementary management practices. The primary classes of ectoparasiticides approved for sheep include organophosphates, pyrethroids, and macrocyclic lactones. Each product has specific label directions regarding dosage, route of administration, and withdrawal periods.
• Organophosphates (e.g., diazinon, coumaphos) are applied as pour‑on or spray formulations. Recommended concentration typically ranges from 0.5 % to 1 % active ingredient, applied to the fleece at a rate of 5 mL per kilogram of body weight. Withdrawal time varies from 7 to 14 days depending on the compound.
• Pyrethroids (e.g., permethrin, deltamethrin) are offered as pour‑on, spray, or injectable preparations. Standard dosage is 0.5 mL per kilogram for pour‑on products, with a 3‑day withdrawal for meat and 7 days for milk. Pyrethroids provide rapid knock‑down of adult lice but may select for resistant populations if used repeatedly.
• Macrocyclic lactones (e.g., ivermectin, moxidectin) are administered subcutaneously or orally. Typical dosing is 0.2 mg kg⁻¹ for ivermectin and 0.2–0.4 mg kg⁻¹ for moxidectin, with a 30‑day withdrawal for meat. These agents affect both adult lice and immature stages, offering broader coverage but requiring careful rotation with other classes to delay resistance.
In addition to chemical treatments, non‑chemical measures enhance long‑term efficacy:
– Regular shearing reduces habitat suitability for lice. – Maintaining low stocking density limits cross‑infection. – Implementing a strategic de‑worming schedule prevents secondary infestations that can compromise animal health. – Monitoring flock for lice prevalence allows timely intervention before heavy infestations develop.
When selecting a product, consider species‑specific label restrictions, pregnancy status, and local regulatory approvals. Record-keeping of treatment dates, products used, and observed efficacy supports responsible parasite management and facilitates compliance with food‑safety standards. «Effective lice control in sheep integrates appropriate ectoparasiticides with sound husbandry practices to achieve sustained health and productivity».