A calf has lice; how should it be treated? - briefly
Apply a licensed ectoparasiticide—such as a pyrethroid pour‑on, spray, or injectable formulation—at the dosage recommended for calves, ensuring thorough coverage of the skin and hair. Treat the housing and bedding simultaneously and repeat the treatment according to the product label to eliminate any surviving lice.
A calf has lice; how should it be treated? - in detail
When a young bovine presents with a lice infestation, immediate intervention is essential to prevent skin irritation, secondary infections, and loss of condition. Effective control involves three coordinated steps: identification, medication, and environmental management.
First, confirm the presence of lice by inspecting the coat, especially around the neck, shoulders, and tail base. Look for live insects, nymphs, or darkened skin patches where insects have fed. A magnifying lens can aid detection.
Second, administer an appropriate ectoparasiticide. Options include:
- Topical pour‑on formulations (e.g., permethrin, pyrethrin‑based products) applied to the backline and neck, then rubbed into the skin.
- Injectable systemic agents (e.g., ivermectin, doramectin) given at the recommended dose per kilogram of body weight, providing protection for up to two weeks.
- Oral drenches containing macrocyclic lactones, useful when topical application is impractical.
Select the product based on veterinary recommendation, withdrawal periods, and resistance history on the farm. Follow label instructions precisely for dosage, application method, and safety precautions.
Third, reduce re‑infestation risk by treating the environment:
- Clean and disinfect housing, focusing on bedding, feeding troughs, and water containers.
- Apply an approved insecticide to the stall surfaces, ensuring proper ventilation.
- Implement a regular grooming schedule to remove debris and expose any remaining parasites.
- Quarantine newly acquired calves for at least 14 days and treat prophylactically before integration.
Monitor the calf for signs of improvement—reduced scratching, healthier skin, and absence of visible lice—over the next 5–7 days. If symptoms persist, repeat treatment according to the product’s re‑treatment interval or consult a veterinarian for alternative therapies.