Drug profile

The FDA adverse-event record for Afoxolaner 2.27% Chewable Tablet (28.3 Mg)

285 FDA reports name Afoxolaner 2.27% Chewable Tablet (28.3 Mg), a high-volume drug in the CVM extract. Species, reactions, and outcomes follow.

#436 of 2,679
by report volume (all drugs)
285
adverse-event reports
2.5%
death-coded share
Dog
most-reported species

Corpus placement

According to the FDA Center for Veterinary Medicine openFDA adverse-event extract, Afoxolaner 2.27% Chewable Tablet (28.3 Mg) ranks #436 of 2679 by total reports (285) and #958 of 1130 by death-coded share (2.5%). National dual: Milbemycin Oxime + Spinosad is #1 of 2679 drugs by total adverse-event reports (149,624) at death-coded-share rank 965 of 1130 drugs with at least 50 reports (2.3%); separately, Atlantic Salmon Transgenic Whole (Opafp-Ghc2 Rdna Construct Inserted Into The A-Locus In The Eo-1A Lineage) is #1 highest death-coded share at 97.8% (report rank #821).

149,624
Milbemycin Oxime + Spinosad reports (#1)
97.8%
Atlantic Salmon Transgenic Whole (Opafp-Ghc2 Rdna Construct Inserted Into The A-Locus In The Eo-1A Lineage) death share (#1)
#436
This drug, reports of 2679
#958
This drug, death share of 1130

Report volume reflects how common a breed or drug is and how often owners and vets file — not actual risk. Death-coded share ranks are limited to entries with enough reports to be meaningful. The two maps do not agree at #1.

Release-over-release change

What changed in the latest FDA data snapshot

PlainBreed reconstructed the prior snapshot from dated openFDA partitions through 2025 Q4, then compared it with the 2026-07-27 openFDA export. Afoxolaner 2.27% Chewable Tablet (28.3 Mg) has 285 reports now versus 285 in that prior snapshot: 0 the same number of (0.0%).

Report change
+0
Death-coded reports
+0
Death-coded share
+0.0 pts

This compares reported-event counts in two source snapshots. It does not establish a change in real-world risk, product safety, or disease incidence.

Subscribe to Afoxolaner 2.27% Chewable Tablet (28.3 Mg) changes

Signature read: 285 reports place Afoxolaner 2.27% Chewable Tablet (28.3 Mg) in the upper third of FDA AER volume (#436 of 2,679).

Important: Adverse event reports do not establish that a drug caused or contributed to the event. Consult your veterinarian before making treatment decisions.
285
Total Reports
7
Deaths Reported
2.5%
Death-coded share of reports

Active Ingredients

Afoxolaner 2.27% Chewable Tablet (28.3 Mg)

Administration Routes

OralUnknown

Species Affected

Dog 284
Fox 1

Most Affected Breeds

Shih Tzu 29
Maltese 22
Crossbred Canine/dog 21
Dog (unknown) 17
Spaniel - King Charles Cavalier 16
Terrier - Yorkshire 16
Terrier - Jack Russell 15
Dachshund (unspecified) 9
Bichon Frise 7
Poodle - Miniature 7

Most Reported Reactions

Vomiting 85
Skin disorders NOS 54
Pruritus 42
Diarrhoea 33
Lethargy (see also Central nervous system depression in 'Neurological') 29
Lack of efficacy (ectoparasite) - tick NOS 28
Lack of efficacy (ectoparasite) - flea 27
Erythema (for urticaria see Immune SOC) 18
Anorexia 18
Behavioural disorder NOS 11
Apathy 11
Itching 10

Outcome Breakdown

Recovered/Normal
150 (52.6%)
Outcome Unknown
117 (41.1%)
Ongoing
9 (3.2%)
Died
6 (2.1%)
Recovered with Sequela
2 (0.7%)
Euthanized
1 (0.4%)

Afoxolaner 2.27% Chewable Tablet (28.3 Mg): low death-coded share in the FDA AER row

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.

High-volume nationwide drug peers

Two openFDA-derived peer sets for Afoxolaner 2.27% Chewable Tablet (28.3 Mg), both floored at ≥50 reports so the neighborhoods stay in the advertised mass.

Similar death-coded share

Nearest other drugs by death-coded share (2.5% here), distinct from the volume row.

What to do with this drug

  • Compare Afoxolaner 2.27% Chewable Tablet (28.3 Mg)'s report volume and death-coded share against similar drugs nationwide. See similar drugs
  • Read how death-coded share differs from a mortality rate before drawing conclusions. Understanding adverse events
  • Browse the full drug directory to compare report counts across products. All drugs

A report does not prove a drug caused the reaction; consult a veterinarian before acting on this data.

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

openFDA Animal & Veterinary Adverse Events (FDA CVM) for Afoxolaner 2.27% Chewable Tablet (28.3 Mg) (#436 of 2,679 by report volume); death-coded 2.5%. PlainBreed drug row · report volume stamp 285 · vintage 2025.

Informational only. FDA adverse-event reports are voluntary and do not prove causation; consult a veterinarian before acting on them. Verify with FDA CVM →