Vetdrugs 2.0
Drug library

Cypermethrin

Synthetic pyrethroid ectoparasiticide

Cypermethrin

Cypermethrin is a synthetic type II pyrethroid used in external parasite-control products. Veterinary formulations include species-specific pour-ons, sprays and dips for livestock. Applications cover selected ticks, lice and flies, including sheep blowfly-strike control. Isomer composition and delivery system influence the product’s parasite spectrum and persistence.

Group

Synthetic pyrethroid ectoparasiticide

Mechanism of Action

Cypermethrin prolongs activation of arthropod voltage-gated sodium channels and delays restoration of normal nerve-membrane potential. Repetitive neural excitation progresses to impaired coordination, paralysis and parasite death. Contact exposure at the skin or fleece surface provides ectoparasiticidal activity, with persistence determined partly by the formulation and surface distribution.

Dose Rates

Sheep

Use / stageDoseRouteScheduleInstructions
External parasite controlReference onlyTOPICALUse the exact Ectofly 12.5 mg/mL pour-on label for indication-specific weight/application tables and nozzle choice. This record does not supply a universal mL/kg or spray dilution.

Indications

Contraindications

Interactions

Adverse effects

Toxicity

Remove contaminated product and provide supportive treatment for pyrethroid neurotoxicity; control tremors and temperature.

Preparations

PreparationFormStrengthRoute
Ectofly pour-on 12.5 mg/mL
High-cis 80:20 cypermethrin sheep pour-on; not an injectable or a ready-made dilution for other products.
Other12.5 mg / mLTOPICAL

Monitoring and Administration

Do not infer a systemic mg/kg dose from dip concentration. Application volume, nozzle, wool length and body area are integral to treatment.

Keep sheep away from watercourses after treatment as directed; cypermethrin is highly toxic to aquatic organisms.

Use gloves and avoid contaminating feed or drinking water.

Veterinary use

For veterinary reference. Confirm the indication, dose, route, interval, product strength and any applicable withdrawal period before administration.