VetMasterJiAntiparasitic · Drug monograph
Afoxolaner: veterinary dose and monograph
Afoxolaner is a veterinary antiparasitic. Monthly isoxazoline flea and tick chew — palatable beef-flavoured tablet that kills fleas before they can lay viable eggs and controls common ticks. Indications include flea infestation — monthly control and prevention; tick infestation (Dermacentor, Ixodes, Rhipicephalus, Amblyomma); aids control of sarcoptic / demodectic mange (off-label). This monograph lists 9 reference doses for dogs, cats, pigs and birds, each with route, frequency and source, plus meat and milk withdrawal periods for food animals.
At a glance
- Drug class
- Antiparasitic
- Also known as
- NexGard
- Species with doses
- Dogs, Cats, Pigs and Birds
- General dose range
- 2.5–6.3 mg/kg PO monthly — check the species tables for the indication
- Routes
- PO
- Last reviewed
- 1 October 2026
Indications
- Flea infestation — monthly control and prevention
- Tick infestation (Dermacentor, Ixodes, Rhipicephalus, Amblyomma)
- Aids control of sarcoptic / demodectic mange (off-label)
Afoxolaner dose by species
Doses are per administration unless stated. mg/kg doses scale with body weight; per-animal, per-quarter and infusion-rate doses are shown as the reference writes them.
Dogs
| Indication | Dose | Route | Frequency | Duration |
|---|---|---|---|---|
| Flea / tick control | 2.5–6.3 mg/kg | PO | one chew per weight band monthly | — |
| Generalised demodicosis — days 0, 14, 28, 56 | 2.5 mg/kg | PO | days 0, 14, 28 and 56 | — |
| Generalised demodicosis — monthly | 2.7–7 mg/kg | PO | monthly until 2 negative scrapings 1 month apart | — |
| Sarcoptic mange | 2.5 mg/kg | PO | days 0 and 28 | — |
| Otodectes (ear mites) | 2.5 mg/kg | PO | once, or monthly for 2 months | — |
- Flea / tick control: Papich 5e: 2.5 mg/kg PO once monthly (label bands deliver 2.5–6.3 mg/kg); for Demodex it has been given more frequently. Plumb’s 10e p.17 (label dosage; FDA-approved): minimum 2.5 mg/kg PO once a month, by weight-band tablet, for dogs ≥8 weeks and ≥1.8 kg. Papich 5e gives no cat dose; Plumb’s 10e gives extra-label cat doses (see Feline rows).
- Generalised demodicosis — days 0, 14, 28, 56: Plumb’s 10e p.17 (extra-label): at least 2.5 mg/kg PO on days 0, 14, 28 and 56.
- Generalised demodicosis — monthly: Plumb’s 10e p.17 (extra-label): 2.7–7 mg/kg PO once a month until 2 negative skin scrapings are obtained 1 month apart.
- Sarcoptic mange: Plumb’s 10e p.17 (extra-label): at least 2.5 mg/kg PO on days 0 and 28.
- Otodectes (ear mites): Plumb’s 10e p.17 (extra-label): 2.5 mg/kg PO once, or once monthly for 2 months.
Cats
| Indication | Dose | Route | Frequency | Duration |
|---|---|---|---|---|
| Otodectes (ear mites) | 2.5 mg/kg | PO | single dose | — |
| Cat flea (experimental) | 2.5 mg/kg | PO | single dose | — |
- Otodectes (ear mites): Plumb’s 10e p.17 (extra-label): 2.5 mg/kg PO as a single dose. Not approved in cats; Papich 5e gives no cat dose.
- Cat flea (experimental): Plumb’s 10e p.17 (extra-label): under experimental conditions, 2.5 mg/kg PO as a single dose for Ctenocephalides felis. Not approved in cats.
Pigs
| Indication | Dose | Route | Frequency | Duration | Withdrawal |
|---|---|---|---|---|---|
| Sarcoptes scabiei var suis | 2.5 mg/kg | PO | single dose | — | Withdrawal NOT established — treat as extra-label |
- Sarcoptes scabiei var suis: Plumb’s 10e p.17 (extra-label): 2.5 mg/kg PO as a single dose. Not approved in food animals — no withdrawal is established; obtain a FARAD estimate before slaughter.
Birds
| Indication | Dose | Route | Frequency | Duration |
|---|---|---|---|---|
| Bird louse (Goniodes pavonis — peafowl) | 2.5 mg/kg | PO | single dose | — |
- Bird louse (Goniodes pavonis — peafowl): Plumb’s 10e p.17 (extra-label): 2.5 mg/kg PO as a single dose for the peafowl louse Goniodes pavonis.
Contraindications
Caution in dogs with a seizure history (isoxazoline class effect). Not established < 8 weeks / < 2 kg. Hypersensitivity.
Species-specific warnings
Dogs: Isoxazoline class — tremor / ataxia / seizures reported; caution in dogs with a seizure history.
Adverse effects
- Vomiting, diarrhoea, inappetence (mild)
- Lethargy, pruritus
- Rare neurological signs (tremor, ataxia, seizure)
Drug interactions
- No clinically significant interactions reported; routinely paired with a macrocyclic-lactone heartworm preventive (e.g. NexGard Spectra)
- Highly protein-bound — theoretical displacement only
Pregnancy and lactation
Safety in breeding, pregnant or lactating dogs not established for the standalone product — use only if benefit outweighs risk.
Monitoring
- Neurological status in epileptic dogs
- Monthly dosing compliance for continuous protection
Toxicity and overdose
Wide safety margin; overdose is usually well tolerated. Class effect: occasional neurological signs (tremor, ataxia, seizures), chiefly in seizure-prone dogs.
Clinical pearls
- Monthly dosing keeps it simple to combine with heartworm prevention (e.g. as NexGard Spectra where available)
- Effective off-label for demodicosis at the standard monthly dose — a convenient alternative to daily ivermectin
- Dose by weight band; counsel seizure-prone dogs as for any isoxazoline
Mechanism of action
Isoxazoline. Blocks arthropod GABA- and glutamate-gated chloride channels → neuronal hyperexcitation and death of fleas and ticks, with high selectivity for invertebrate over mammalian channels.
Formulations and products
- NexGard chewable 11.3–136 mg (by bodyweight band)
- NexGard (Boehringer Ingelheim) — 11.3 / 28.3 / 68 / 136 mg, Beef-flavoured chewable
Storage
Store at room temperature in the original packaging.
Before you use this dose
Reference doses for veterinary professionals. Confirm the dose against the product label, the patient’s condition, current guidance and local regulations before use; the attending veterinarian remains responsible for every clinical decision.
Frequently asked questions
What is the dose of Afoxolaner for dogs?
Reference doses for Afoxolaner in dogs: 2.5–6.3 mg/kg PO one chew per weight band monthly (Flea / tick control); 2.5 mg/kg PO days 0, 14, 28 and 56 (Generalised demodicosis — days 0, 14, 28, 56); 2.7–7 mg/kg PO monthly until 2 negative scrapings 1 month apart (Generalised demodicosis — monthly); 2.5 mg/kg PO days 0 and 28 (Sarcoptic mange); and 1 more indication-specific doses listed on this page. Confirm against the label and the patient before use.
What is the dose of Afoxolaner for cats?
Reference doses for Afoxolaner in cats: 2.5 mg/kg PO single dose (Otodectes (ear mites)); 2.5 mg/kg PO single dose (Cat flea (experimental)). Confirm against the label and the patient before use.
What is the dose of Afoxolaner for pigs?
Reference doses for Afoxolaner in pigs: 2.5 mg/kg PO single dose (Sarcoptes scabiei var suis). Confirm against the label and the patient before use.
What is the withdrawal period for Afoxolaner?
Pigs, PO (Sarcoptes scabiei var suis): Withdrawal NOT established — treat as extra-label. Follow the product label and national regulations where they differ.
When should Afoxolaner not be used?
Caution in dogs with a seizure history (isoxazoline class effect). Not established < 8 weeks / < 2 kg. Hypersensitivity.
What are the side effects of Afoxolaner in animals?
Vomiting, diarrhoea, inappetence (mild); Lethargy, pruritus; Rare neurological signs (tremor, ataxia, seizure).
Sources
- Plumb's Veterinary Drug Handbook
- Papich, Papich Handbook of Veterinary Drugs, 5th edition
Last reviewed · VetMasterJi