Drug profile

The FDA adverse-event record for Fipronil

1,784 FDA reports name Fipronil, a high-volume drug in the CVM extract. Species, reactions, and outcomes follow.

#120 of 2,679
by report volume (all drugs)
1,784
adverse-event reports
4.1%
death-coded share
Dog
most-reported species

Corpus placement

According to the FDA Center for Veterinary Medicine openFDA adverse-event extract, Fipronil ranks #120 of 2679 by total reports (1,784) and #839 of 1130 by death-coded share (4.1%). 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)
#120
This drug, reports of 2679
#839
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. Fipronil has 1,784 reports now versus 1,780 in that prior snapshot: 4 more (0.2%).

Report change
+4
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 Fipronil changes

Signature read: 1,784 reports place Fipronil in the upper third of FDA AER volume (#120 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.
1,784
Total Reports
73
Deaths Reported
4.1%
Death-coded share of reports

Active Ingredients

Fipronil

Administration Routes

TopicalUnknownOralCutaneousOtherSubcutaneousTransdermalAuricular (Otic)

Species Affected

Dog 1,309
Cat 469
Unknown 5
Human 1

Most Affected Breeds

Domestic Shorthair 252
Retriever - Labrador 141
Crossbred Canine/dog 75
Domestic Longhair 70
Terrier - Yorkshire 57
Dog (unknown) 53
Retriever - Golden 51
Shepherd Dog - German 50
Shih Tzu 50
Cat (unknown) 48

Most Reported Reactions

Lack of efficacy (ectoparasite) - flea 462
Emesis 254
Lethargy (see also Central nervous system depression in 'Neurological') 220
Vomiting 205
Lack of efficacy - NOS 124
Diarrhoea 110
Panting 83
Other abnormal test result NOS 74
Lack of efficacy (flea) 72
Seizure NOS 67
Pruritus 62
Behavioural disorder NOS 62

Outcome Breakdown

Outcome Unknown
706 (39.7%)
Recovered/Normal
632 (35.5%)
Ongoing
304 (17.1%)
Recovered with Sequela
63 (3.5%)
Died
41 (2.3%)
Euthanized
32 (1.8%)

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

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 Fipronil (#120 of 2,679 by report volume); death-coded 4.1%. PlainBreed drug row · report volume stamp 1,784 · 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 →