Drug profile

The FDA adverse-event record for Afoxolaner

52,656 adverse-event reports submitted to the FDA Center for Veterinary Medicine reference Afoxolaner. See the species affected, top reactions, and outcomes below.

52,656
adverse-event reports
3.1%
death-coded share
Dog
most-reported species
12,941
Vomiting - top reaction
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Important: Adverse event reports do not establish that a drug caused or contributed to the event. Consult your veterinarian before making treatment decisions.
52,656
Total Reports
1,653
Deaths Reported
3.1%
Death Rate

Active Ingredients

Afoxolaner

Administration Routes

OralUnknownOtherTopicalParenteralSubcutaneousOphthalmicTransplacentalTransdermalAuricular (Otic)

Species Affected

Dog 49,011
Unknown 3,492
Human 81
Cat 64
Other Canids 3
Other 2
Wolf 1
Spider 1
Goat 1

Most Affected Breeds

Retriever - Labrador 5,367
Dog (unknown) 4,871
Unknown 3,625
Retriever - Golden 3,303
Crossbred Canine/dog 2,283
Shepherd Dog - German 2,006
Chihuahua 1,854
Shih Tzu 1,570
Terrier - Yorkshire 1,547
Shepherd Dog - Australian 1,295

Most Reported Reactions

Vomiting 12,941
Lethargy (see also Central nervous system depression in 'Neurological') 5,200
Diarrhoea 4,727
Lack of efficacy (ectoparasite) - tick NOS 4,524
Lack of efficacy (ectoparasite) - flea 4,016
Seizure NOS 3,781
Lack of efficacy (bacteria) - Borrelia 2,910
Lack of efficacy (bacteria) - NOS 2,607
Lack of efficacy (tick) 2,200
Pruritus 1,920
Tablets, Abnormal 1,742
Itching 1,722

Outcome Breakdown

Outcome Unknown
28,240 (57.5%)
Recovered/Normal
15,020 (30.6%)
Ongoing
4,090 (8.3%)
Died
971 (2.0%)
Euthanized
683 (1.4%)
Recovered with Sequela
111 (0.2%)

Afoxolaner Adverse Event Insights

52,656 reports name Afoxolaner; 1,653 recorded a death outcome (3.1% of reported events, not a population-level mortality rate). Active ingredient: Afoxolaner. Administration routes: Oral, Unknown, Other, Topical.

By species: Dog (49,011 reports), Unknown (3,492 reports), Human (81 reports). By breed: Retriever - Labrador (5,367), Dog (unknown) (4,871), Unknown (3,625).

Leading clinical signs: Vomiting (12,941), Lethargy (see also Central nervous system depression in 'Neurological') (5,200), Diarrhoea (4,727), Lack of efficacy (ectoparasite) - tick NOS (4,524). Outcome, 49,115 coded reports: Outcome Unknown leads at 57.5%.

Read these counts as reporting volume, not risk: per our methodology, a widely-prescribed drug will rack up more raw FDA reports in a given year than a rarely-used one at an identical true rate, so we recommend comparing within similar-exposure products rather than across the full 2025 catalog.

Source: FDA Center for Veterinary Medicine openFDA Animal & Veterinary Adverse Events (CVM AER) · 2025

Every figure on PlainBreed is rendered directly from FDA openFDA adverse event data, no number is typed in by an editor. This page draws directly on FDA openFDA data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.