Drug profile

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

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

#207 of 2,679
by report volume (all drugs)
834
adverse-event reports
6.1%
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 #207 of 2679 by total reports (834) and #729 of 1130 by death-coded share (6.1%). 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)
#207
This drug, reports of 2679
#729
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 834 reports now versus 831 in that prior snapshot: 3 more (0.4%).

Report change
+3
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: 834 reports place Fipronil + S-Methoprene in the upper third of FDA AER volume (#207 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.
834
Total Reports
51
Deaths Reported
6.1%
Death-coded share of reports

Active Ingredients

FipronilFipronil + S-MethopreneS-Methoprene

Administration Routes

TopicalOtherUnknownOralSubconjunctival

Species Affected

Dog 781
Cat 52
Goat 1

Most Affected Breeds

Dog (unknown) 56
Retriever - Labrador 54
Retriever - Golden 49
Crossbred Canine/dog 40
Chihuahua 39
Spaniel - King Charles Cavalier 32
Terrier - Yorkshire 31
Shepherd Dog - German 28
Shih Tzu 23
Domestic Shorthair 22

Most Reported Reactions

Lack of efficacy (ectoparasite) - flea 263
Vomiting 86
Seizure NOS 59
Lack of efficacy (ectoparasite) - tick NOS 52
Lethargy (see also Central nervous system depression in 'Neurological') 49
Diarrhoea 46
Death 28
Shaking 27
Behavioural disorder NOS 25
Lack of efficacy (bacteria) - NOS 25
Lack of efficacy (bacteria) - Borrelia 25
Scratching 24

Outcome Breakdown

Outcome Unknown
518 (61.9%)
Recovered/Normal
199 (23.8%)
Ongoing
67 (8.0%)
Died
31 (3.7%)
Euthanized
20 (2.4%)
Recovered with Sequela
2 (0.2%)

Fipronil + S-Methoprene: high report volume 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 (#207 of 2,679 by report volume); death-coded 6.1%. PlainBreed drug row · report volume stamp 834 · 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 →