Fipronil + S-Methoprene
812 adverse event reports submitted to the FDA
Active Ingredients
Administration Routes
Species Affected
Most Affected Breeds
Most Reported Reactions
Outcome Breakdown
Data Summary
| Metric | Value |
|---|---|
| Total adverse event reports | 812 |
| Reports involving death | 49 |
| Case-fatality rate (reported events) | 600.0% |
| Distinct species in reports | 3 |
| Distinct breeds in reports | 20 |
| Distinct reactions reported | 20 |
| Active ingredients on file | 3 |
Source: FDA Center for Veterinary Medicine — Adverse Event Reporting (CVM AER). Counts reflect voluntary reports only.
Fipronil + S-Methoprene Adverse Event Insights
The FDA Center for Veterinary Medicine database currently holds 812 adverse event reports referencing Fipronil + S-Methoprene, including 49 reports in which the animal died — a 600.0% case-fatality figure among reported events only, not a population-level mortality rate. Active ingredients on file: Fipronil, Fipronil + S-Methoprene, S-Methoprene. Reported administration routes include Topical, Other, Unknown, Oral. These numbers reflect voluntary submissions from pet owners, veterinarians, and manufacturers and therefore under-represent mild events and over-represent severe ones — a pattern the FDA has documented repeatedly for pharmacovigilance datasets.
The species most frequently named in Fipronil + S-Methoprene reports are Dog (762 reports), Cat (49 reports), Goat (1 reports), with Dog accounting for the largest share. Within those species, Dog (unknown) (54), Retriever - Labrador (51), Retriever - Golden (47) appear most often — though breed popularity and ownership density shape these counts as much as any drug-specific sensitivity. This distribution matters because the same active ingredient can behave very differently across body sizes, ages, and species physiology.
The most commonly reported clinical signs associated with Fipronil + S-Methoprene are Lack of efficacy (ectoparasite) - flea (255), Vomiting (86), Seizure NOS (58), Lack of efficacy (ectoparasite) - tick NOS (52). Of the 815 reports with a coded outcome, Outcome Unknown is the leading category at 62.0%. Because FDA adverse event data describes correlation rather than causation, these figures are best used to frame informed questions with a veterinarian and to compare reporting patterns across related products — not as a standalone safety verdict on Fipronil + S-Methoprene.
Source: FDA Center for Veterinary Medicine — Adverse Event Reports FDA Center for Veterinary Medicine — Adverse Event Reports Data reflects voluntary submissions and may not represent actual incidence rates
Read our methodology — how this data is sourced, computed, and verified.