Drug profile

The FDA adverse-event record for Afoxolaner 28.3 Mg Chewable Tablets

2,155 adverse-event reports submitted to the FDA Center for Veterinary Medicine reference Afoxolaner 28.3 Mg Chewable Tablets. See the species affected, top reactions, and outcomes below.

2,155
adverse-event reports
1.7%
death-coded share
Dog
most-reported species
468
Lack of efficacy (tick) - 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.
2,155
Total Reports
37
Deaths Reported
1.7%
Death Rate

Active Ingredients

Afoxolaner 28.3 Mg Chewable Tablets

Administration Routes

OralUnknownOther

Species Affected

Dog 1,958
Unknown 193
Human 2
Other 1
Cat 1

Most Affected Breeds

Shih Tzu 303
Crossbred Canine/dog 215
Unknown 205
Dog (unknown) 132
Lhasa Apso 131
Poodle - Miniature 93
Poodle - Toy 81
Terrier - Yorkshire 79
Maltese 69
Mixed (Dog) 61

Most Reported Reactions

Lack of efficacy (tick) 468
Skin disorders NOS 457
Vomiting 452
Lack of efficacy (flea) 301
Diarrhoea 167
Lethargy (see also Central nervous system depression in 'Neurological') 151
Pruritus 119
Lack of efficacy (ectoparasite) - NOS 86
Emesis 85
Anorexia 70
Scratching 64
Overdose 56

Outcome Breakdown

Outcome Unknown
1,226 (62.4%)
Recovered/Normal
605 (30.8%)
Ongoing
90 (4.6%)
Died
32 (1.6%)
Recovered with Sequela
6 (0.3%)
Euthanized
5 (0.3%)

Afoxolaner 28.3 Mg Chewable Tablets Adverse Event Insights

2,155 reports name Afoxolaner 28.3 Mg Chewable Tablets; 37 recorded a death outcome (1.7% of reported events, not a population-level mortality rate). Active ingredient: Afoxolaner 28.3 Mg Chewable Tablets. Administration routes: Oral, Unknown, Other.

By species: Dog (1,958 reports), Unknown (193 reports), Human (2 reports). By breed: Shih Tzu (303), Crossbred Canine/dog (215), Unknown (205).

Leading clinical signs: Lack of efficacy (tick) (468), Skin disorders NOS (457), Vomiting (452), Lack of efficacy (flea) (301). Outcome, 1,964 coded reports: Outcome Unknown leads at 62.4%.

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.