# Afoxolaner for Animals: Mechanism, Doses by Species & Brands

> Afoxolaner is an isoxazoline flea and tick drug for dogs, given orally once a month at a minimum of 2.5 mg/kg.

- Source page: https://wevet.in/active-ingredients/afoxolaner/
- Type: Active ingredient
- Publisher: WeVet
- Updated: 2026-11-02
- Medically reviewed by: Dr. Ravi Baraiya, B.V.Sc. (2026-11-02)
- Audience: veterinarians and veterinary students

Afoxolaner is an isoxazoline flea and tick drug for dogs, given orally once a month at a minimum of 2.5 mg/kg [1].

- Class: Isoxazoline ectoparasiticide
- Brands: NexGard

## Dose by species

| Species | Use | Dose | Route | How often | Basis |
|---|---|---|---|---|---|
| Dogs | Fleas and ticks (Minimum dose; given as whole chewables by weight band.) | 2.5 mg/kg [1] | PO | Once a month | Label |

## Uses

- Dogs and puppies from 8 weeks and 4 lb: fleas and several tick species for one month [1].

## Mechanism of action

Afoxolaner binds to and inhibits insect and acarine ligand-gated chloride channels, especially GABA-gated ones; the resulting hyperexcitation kills fleas and ticks [1].

## Safety

- Isoxazolines have been associated with neurologic adverse reactions including tremors, ataxia and seizures — use with caution in dogs with a history of seizures [1].
- Not evaluated in dogs under 8 weeks of age or under 4 lb [1].


## Frequently asked questions

### What is the afoxolaner dose for dogs?

At least 2.5 mg/kg orally once a month [1].

## References

[1] NEXGARD (afoxolaner) chewable — label — DailyMed (US NLM) — FDA-approved label, Boehringer Ingelheim (2026). https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=e10f7434-d00c-44de-af79-7b0886b2e948

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Numbers in [brackets] cite the references above. For veterinary professionals. Information supports — never replaces — clinical judgement; always check the current product label and local regulations.
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