Drug profile

The FDA adverse-event record for Afoxolaner

53,894 FDA reports name Afoxolaner, a high-volume drug in the CVM extract. Species, reactions, and outcomes follow.

#4 of 2,679
by report volume (all drugs)
53,894
adverse-event reports
3.2%
death-coded share
Dog
most-reported species

Corpus placement

According to the FDA Center for Veterinary Medicine openFDA adverse-event extract, Afoxolaner ranks #4 of 2679 by total reports (53,894) and #901 of 1130 by death-coded share (3.2%). 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)
#4
This drug, reports of 2679
#901
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 has 53,894 reports now versus 53,474 in that prior snapshot: 420 more (0.8%).

Report change
+420
Death-coded reports
+13
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 changes

Signature read: 53,894 reports place Afoxolaner in the upper third of FDA AER volume (#4 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.
53,894
Total Reports
1,702
Deaths Reported
3.2%
Death-coded share of reports

Active Ingredients

Afoxolaner

Administration Routes

OralUnknownOtherTopicalParenteralOphthalmicSubcutaneousTransplacentalTransdermalAuricular (Otic)

Species Affected

Dog 50,169
Unknown 3,563
Human 82
Cat 72
Other Canids 3
Other 2
Wolf 1
Spider 1
Goat 1

Most Affected Breeds

Retriever - Labrador 5,494
Dog (unknown) 4,946
Unknown 3,700
Retriever - Golden 3,405
Crossbred Canine/dog 2,358
Shepherd Dog - German 2,049
Chihuahua 1,896
Shih Tzu 1,599
Terrier - Yorkshire 1,563
Shepherd Dog - Australian 1,342

Most Reported Reactions

Vomiting 13,114
Lethargy (see also Central nervous system depression in 'Neurological') 5,200
Diarrhoea 4,787
Lack of efficacy (ectoparasite) - tick NOS 4,692
Lack of efficacy (ectoparasite) - flea 4,122
Seizure NOS 3,883
Lack of efficacy (bacteria) - Borrelia 3,082
Lack of efficacy (bacteria) - NOS 2,611
Lack of efficacy (tick) 2,200
Pruritus 1,922
Tablets, Abnormal 1,803
Itching 1,747

Outcome Breakdown

Outcome Unknown
28,872 (57.4%)
Recovered/Normal
15,278 (30.4%)
Ongoing
4,318 (8.6%)
Died
995 (2.0%)
Euthanized
708 (1.4%)
Recovered with Sequela
112 (0.2%)

Afoxolaner: 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, both floored at ≥50 reports so the neighborhoods stay in the advertised mass.

Similar report volume

Nearest other drugs by FDA report count (53,894 here).

Similar death-coded share

Nearest other drugs by death-coded share (3.2% here), distinct from the volume row.

What to do with this drug

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 (#4 of 2,679 by report volume); death-coded 3.2%. PlainBreed drug row · report volume stamp 53,894 · 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 →