Drug profile

The FDA adverse-event record for Fipronil And (S)-Methoprene

23 adverse-event reports submitted to the FDA Center for Veterinary Medicine reference Fipronil And (S)-Methoprene. Species, reactions, and outcomes follow.

#1651 of 2,679
by report volume (all drugs)
23
adverse-event reports
4.3%
death-coded share
Cat
most-reported species
Verify with FDA CVM →

Corpus placement

According to the FDA Center for Veterinary Medicine openFDA adverse-event extract, Fipronil And (S)-Methoprene ranks #1638 of 2679 by total reports (23). Death-coded-share rank requires at least 50 reports. 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)
#1638
This drug, reports of 2679

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 And (S)-Methoprene has 23 reports now versus 23 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 Fipronil And (S)-Methoprene changes

Signature read: death-coded report count at 1 is the most distinctive stamp on Fipronil And (S)-Methoprene's FDA AER row.

Important: Adverse event reports do not establish that a drug caused or contributed to the event. Consult your veterinarian before making treatment decisions.
23
Total Reports
1
Deaths Reported
4.3%
Death-coded share of reports

Active Ingredients

Fipronil And (S)-Methoprene

Administration Routes

TopicalUnknown

Species Affected

Cat 14
Dog 9

Most Affected Breeds

Domestic Shorthair 5
Cat (unknown) 5
Persian 3
Shepherd Dog - German 2
Deutsche Dogge, Great Dane 1
Sheepdog - Shetland 1
Maine Coon 1
Dachshund (unspecified) 1
Chihuahua 1
Pug 1

Most Reported Reactions

Lack of efficacy (ectoparasite) - flea 11
Panting 3
Pruritus 2
Emesis 1
Conjunctivitis 1
Alopecia NOS 1
Erythema (for urticaria see Immune SOC) 1
Self trauma 1
Application site alopecia 1
Low tear flow 1
Other abnormal test result NOS 1
Drooling 1

Outcome Breakdown

Outcome Unknown
16 (69.6%)
Recovered/Normal
5 (21.7%)
Euthanized
1 (4.3%)
Ongoing
1 (4.3%)

Fipronil And (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.

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 And (S)-Methoprene (#1651 of 2,679 by report volume); death-coded 4.3%. PlainBreed drug row · death-coded report count stamp 1 · 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 →