Fipronil/S-Methoprene
101 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 | 101 |
| Reports involving death | 12 |
| Case-fatality rate (reported events) | 1190.0% |
| Distinct species in reports | 2 |
| Distinct breeds in reports | 20 |
| Distinct reactions reported | 20 |
| Active ingredients on file | 1 |
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 101 adverse event reports referencing Fipronil/S-Methoprene, including 12 reports in which the animal died — a 1190.0% case-fatality figure among reported events only, not a population-level mortality rate. Active ingredient on file: Fipronil/S-Methoprene. Reported administration routes include Topical, 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 (87 reports), Cat (14 reports), with Dog accounting for the largest share. Within those species, Retriever - Labrador (15), Domestic Shorthair (10), Terrier - West Highland White (7) 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 Lethargy (see also Central nervous system depression in 'Neurological') (24), Other abnormal test result NOS (14), Vomiting (12), Diarrhoea (11). Of the 101 reports with a coded outcome, Recovered/Normal is the leading category at 43.6%. 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.