Indoxacarb
Also known as: Activyl Tick Plus
Reviewed by the VetSheet Veterinary TeamUpdated Apr 5, 2026Evidence-based veterinary reference
Doses are a clinical reference for licensed veterinary professionals. Always confirm against the current label and the individual patient.
Dosing by species
🌎 NA — North America🌍 EU — Europe
Dogs
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| Fleas | 15 mg/kg (equivalent to 0.077 ml/kg Activyl or 0.1 ml/ kg Activyl Tick Plus) | topical | monthly | — | 🌍 EU |
Cats
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| Fleas | 25 mg/kg (equivalent to 0.128 ml/kg Activyl) | topical | monthly | — | 🌍 EU |
- Fleas: The combined formulation (with permethrin) is not authorized for cats.
Doses are a clinical reference for licensed veterinary professionals. Always confirm against the current label and the individual patient.
Overview
Treatment of flea infestations (Ctenocephalides felis). Developing stages of fleas in the immediate environment are killed on contact. As indoxacarb is a pro-drug bioactivated by insect enzymes, it is very specific for insect cells. Formulations with permethrin also provide prevention of tick infestations (Ixodes ricinus and Rhipicephalus sanguineus).
Clinical Pearl: If ticks are present on the dog at the time of application, they may not be killed within 48 hours.
Mechanism of action
Acts on voltage-dependent sodium channels in susceptible insects. Indoxacarb is a pro-drug bioactivated by insect enzymes → the active component has a much higher affinity for insect sodium channels → highly specific for insect cells.
Safety & warnings
Contraindications
- Dogs and cats < 8 weeks old
- Dogs < 1.5 kg (< 1.2 kg for Activyl plus)
- Cats < 0.6 kg
- Permethrin combination products must NOT be used on cats
Adverse effects
- Transient pruritus at the site of application
- Gastrointestinal signs (rare)
Precautions
Normal precautions should be observed.
Warning: May be harmful to aquatic organisms. Do not use permethrin-containing products on cats.
Monitoring
- Efficacy of flea/tick control
- Application site reactions
Pharmacokinetics
Metabolism
Bioactivated by insect enzymes into active component.
Overdose
No specific information provided in the monograph.
Available products
Formulations
- Topical spot-on solution: 195 mg/ml (Activyl)
- Topical spot-on solution: 150 mg/ml indoxacarb + permethrin (Activyl Tick Plus)
Veterinary
- Activyl (195 mg/ml spot-on)
- Activyl Tick Plus (150 mg/ml indoxacarb + permethrin spot-on)
Regulatory status
POM-V
POM-V
No regulatory data for: 🇺🇸 US · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
Storage & stability
Normal precautions.
Client information
Apply the spot-on solution directly to the skin. Do not use the dog product (which contains permethrin) on cats, as it is highly toxic to them. The product kills adult fleas and developing stages in the environment. Ticks already on the pet may take up to 48 hours to die. Wash hands after application and avoid allowing pets to swim immediately after application to protect aquatic life.
VetSheet drug reference is intended for licensed veterinary professionals as a clinical decision-support aid, not a substitute for professional judgement or the manufacturer’s current label.