Afoxolaner
Afoxolaner is an oral isoxazoline ectoparasiticide for dogs. It kills susceptible fleas, ticks and mites after parasite exposure to the treated host.
Monthly treatment is used for flea and tick control and for selected mite infestations. Neurologic adverse events can occur even in dogs without a previous seizure history.
Some single-ingredient chew labels specify a minimum exposure of 2.5 mg/kg; others use a 2.7-7 mg/kg weight-band range. Select whole chews with the table for the exact presentation rather than treating a minimum as an exact dose.
Group
Isoxazoline ectoparasiticide
Mechanism of Action
Blockade of arthropod ligand-gated chloride channels disrupts GABA-mediated neurotransmission, causing parasite hyperexcitation and death. Selectivity for arthropod channels does not eliminate neurologic adverse-event risk in dogs.
Dose Rates
Dogs
| Use / stage | Dose | Route | Schedule | Instructions |
|---|---|---|---|---|
| Flea and tick control | 2.7–7 mg/kg | PO | Alternative established weight-band exposure range. Give whole chews monthly using the corresponding product weight table; do not divide tablets. | |
| Demodicosis | 2.7–7 mg/kg | PO | Whole weight-band chews monthly until two negative skin scrapings one month apart; address underlying disease. Do not use a twice-weekly schedule. | |
| Sarcoptic mange | 2.7–7 mg/kg | PO | Whole weight-band chews monthly for two consecutive months, followed by clinical and skin-scraping reassessment. |
Indications
- Treatment and prevention of flea infestations.
- Treatment and control of susceptible tick infestations.
- Treatment of canine demodicosis and sarcoptic mange using supported monthly regimens.
Contraindications
- Use cautiously in dogs with seizures or other neurologic disorders.
- Safety in pregnant, lactating or breeding dogs is not established for the single-ingredient chews described here.
- Do not extrapolate these canine regimens to cats or food-producing animals.
- Young or very small puppies require product-specific eligibility assessment; the 2.5 mg/kg minimum-dose label applies from 8 weeks and 4 lb body weight.
Interactions
- No clinically important interactions were identified with common concomitant treatments in the cited product field studies.
Adverse effects
- Vomiting, diarrhea, anorexia, lethargy or pruritus.
- Tremors, ataxia or seizures, including in dogs without a prior neurologic history.
Toxicity
Overexposure can be associated with gastrointestinal or neurologic signs. There is no specific antidote described; manage clinical signs and review the amount consumed, particularly after accidental access to multiple chews.
Preparations
| Preparation | Form | Strength | Route |
|---|---|---|---|
| NexGard 11.3 mg Chewables Single-ingredient afoxolaner chew. Select whole chews using this presentation’s weight-band table; combination NexGard products are different formulations. | Tablet | 11.3 mg / tablet | PO |
| NexGard 28.3 mg Chewables Single-ingredient afoxolaner chew. Select whole chews using this presentation’s weight-band table; combination NexGard products are different formulations. | Tablet | 28.3 mg / tablet | PO |
| NexGard 68 mg Chewables Single-ingredient afoxolaner chew. Select whole chews using this presentation’s weight-band table; combination NexGard products are different formulations. | Tablet | 68 mg / tablet | PO |
| NexGard 136 mg Chewables Single-ingredient afoxolaner chew. Select whole chews using this presentation’s weight-band table; combination NexGard products are different formulations. | Tablet | 136 mg / tablet | PO |
