Drug profile

The FDA adverse-event record for Fipronil, S-Methoprene

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

#620 of 2,679
by report volume (all drugs)
154
adverse-event reports
1.9%
death-coded share
Dog
most-reported species

Corpus placement

According to the FDA Center for Veterinary Medicine openFDA adverse-event extract, Fipronil, S-Methoprene ranks #619 of 2679 by total reports (154) and #993 of 1130 by death-coded share (1.9%). 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)
#619
This drug, reports of 2679
#993
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, S-Methoprene has 154 reports now versus 153 in that prior snapshot: 1 more (0.7%).

Report change
+1
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, S-Methoprene changes

Signature read: Fipronil, S-Methoprene's 1.9% death-coded share is among the lowest in the openFDA drug corpus.

Important: Adverse event reports do not establish that a drug caused or contributed to the event. Consult your veterinarian before making treatment decisions.
154
Total Reports
3
Deaths Reported
1.9%
Death-coded share of reports

Active Ingredients

Fipronil, S-Methoprene

Administration Routes

TopicalUnknownOralCutaneousOther

Species Affected

Dog 86
Cat 66
Other 2

Most Affected Breeds

Domestic Shorthair 39
Retriever - Labrador 10
Shih Tzu 8
Domestic Longhair 6
Domestic Mediumhair 6
Pug 4
Terrier - Yorkshire 4
Shepherd Dog - German 4
Cat (unknown) 4
Retriever - Golden 3

Most Reported Reactions

Lack of efficacy (ectoparasite) - flea 79
Diarrhoea 18
Lethargy (see also Central nervous system depression in 'Neurological') 17
Scratching 15
Vomiting 12
Lack of efficacy - NOS 8
Panting 7
Drooling 6
Emesis 6
Vocalisation 6
Anorexia 6
Behavioural disorder NOS 6

Outcome Breakdown

Outcome Unknown
96 (62.3%)
Recovered/Normal
36 (23.4%)
Ongoing
19 (12.3%)
Died
3 (1.9%)

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

What to do with this drug

  • Compare Fipronil, S-Methoprene'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 Fipronil, S-Methoprene (#620 of 2,679 by report volume); death-coded 1.9%. PlainBreed drug row · death-coded share stamp 1.9% · 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 →