Active ingredient

Afoxolaner for Animals: Mechanism, Doses by Species & Brands

Q: What is the afoxolaner dose for dogs?

At least 2.5 mg/kg orally once a month.

Reviewed by Dr. Ravi Baraiya, B.V.Sc.Updated 2 Nov 20261 source

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

Drug class: Isoxazoline ectoparasiticide
Sourced doses for: Dogs
Brands on this site: NexGard

Afoxolaner dose calculator

Type the strength printed on your own product. Results are calculated in your browser from the cited doses on this page — always check the label of the product you use.

Afoxolaner 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

What afoxolaner is used for

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

How afoxolaner works (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, contraindications and precautions

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].

Brands that contain afoxolaner

Brand	Company	Contains	Market
NexGard	Boehringer Ingelheim Animal Health	Afoxolaner	USA (FDA label)

Frequently asked questions

What is the afoxolaner dose for dogs?

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

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Medically reviewed by

Dr. Ravi Baraiya, B.V.Sc.

Veterinarian · Reviewed 2 Nov 2026

References

NEXGARD (afoxolaner) chewable — labelDailyMed (US NLM) — FDA-approved label, Boehringer Ingelheim · 2026 · Product label
Passage read from this source
NexGard® is given orally once a month, at the minimum dosage of 1.14 mg/lb (2.5 mg/kg).
This class has been associated with neurologic adverse reactions including tremors, ataxia, and seizures.
Use with caution in dogs with a history of seizures or neurologic disorders.

For veterinary professionals. Information supports — never replaces — clinical judgement; always check the current product label and local regulations.