Permethrin
Permethrin is an external insecticide used in dog products and selected livestock formulations. Concentrated canine products can be fatal to cats.
Group
Pyrethroid ectoparasiticide
Mechanism of Action
Prolongs opening of arthropod voltage-gated sodium channels.
Dose Rates
Dogs
| Use / stage | Dose | Route | Schedule | Instructions |
|---|---|---|---|---|
| Flea, tick and biting-insect control | Reference only | TOPICAL | Once | Do not use in: Cats, Puppies under 7 weeks, Dogs below 1.5 kg; Advantix: use the complete size-matched pipette. At 1.5–4 kg, one 0.4 mL pipette contains 40 mg imidacloprid plus 200 mg permethrin; puppies must be at least 7 weeks. Retreatment and duration depend on parasite and exposure. Never apply to cats. |
Indications
- Canine flea, tick and biting-insect control with an appropriate product
Contraindications
- Cats for the concentrated canine preparation
- Advantix use in puppies under 7 weeks or below 1.5 kg
- Hypersensitivity
Interactions
- Avoid unplanned concurrent neurotoxic insecticides.
Adverse effects
- Local irritation
- Salivation
- Tremors or seizures after poisoning
Toxicity
Feline exposure is an emergency. Remove product from skin, control tremors and temperature and provide supportive care.
Preparations
| Preparation | Form | Strength | Route |
|---|---|---|---|
| Advantix 40 mg + 200 mg spot-on Whole 0.4 mL pipette for eligible dogs 1.5–4 kg. Contains permethrin cis:trans 40:60. Not for cats; do not use as a free-volume single-active preparation. | Other | permethrin 200 mg / 0.4 mL + imidacloprid 40 mg / 0.4 mL | TOPICAL |
Monitoring and Administration
Keep cats away from treated dogs until the application site is dry. Do not let cats groom treated dogs.
Use the exact complete pipette for body weight, on intact skin. Product combinations are not generic single-active dose calculations.
Advantix 40 mg + 200 mg contains 0.4 mL and is for dogs 1.5–4 kg that are at least 7 weeks old. Larger dogs require their corresponding product size.
Avoid surface-water exposure for at least 48 hours after Advantix treatment.
Permethrin is also present in livestock pour-ons, dusts and sprays for flies, lice, mites, mosquitoes, ticks and keds; these are not interchangeable with dog spot-ons. Avoid eyes and mucous membranes and wear gloves when applying.
Do not extrapolate a dose between a 45% spot-on, shampoo, dilute spray or imidacloprid combination; use the complete actual formulation and host instructions.