Drug profile

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

10 adverse-event reports submitted to the FDA Center for Veterinary Medicine reference (S)-Methoprene/Fipronil. See the species affected, top reactions, and outcomes below.

10
adverse-event reports
0.0%
death-coded share
Dog
most-reported species
4
Hyperactivity - top reaction
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Important: Adverse event reports do not establish that a drug caused or contributed to the event. Consult your veterinarian before making treatment decisions.
10
Total Reports
0
Deaths Reported
0.0%
Death Rate

Active Ingredients

(S)-Methoprene/Fipronil

Administration Routes

TopicalCutaneous

Species Affected

Dog 6
Cat 4

Most Affected Breeds

Domestic Shorthair 3
Spaniel - Cocker American 2
Boxer (German Boxer) 1
Shih Tzu 1
Pug 1
Domestic Mediumhair 1
Spaniel - King Charles Cavalier 1

Most Reported Reactions

Hyperactivity 4
Scratching 4
Excessive licking and/or grooming 4
Lack of efficacy - NOS 3
Lack of efficacy (ectoparasite) - flea 3
Injection site pain 1
Injection site irritation 1
INEFFECTIVE, OTHER DRUG(S) 1
Panting 1
Vomiting 1
Lethargy (see also Central nervous system depression in 'Neurological') 1
Emesis 1

Outcome Breakdown

Ongoing
9 (90.0%)
Recovered/Normal
1 (10.0%)

(S)-Methoprene/Fipronil Adverse Event Insights

10 reports name (S)-Methoprene/Fipronil; 0 recorded a death outcome (0.0% of reported events, not a population-level mortality rate). Active ingredient: (S)-Methoprene/Fipronil. Administration routes: Topical, Cutaneous.

By species: Dog (6 reports), Cat (4 reports). By breed: Domestic Shorthair (3), Spaniel - Cocker American (2), Boxer (German Boxer) (1).

Leading clinical signs: Hyperactivity (4), Scratching (4), Excessive licking and/or grooming (4), Lack of efficacy - NOS (3). Outcome, 10 coded reports: Ongoing leads at 90.0%.

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.

Source: FDA Center for Veterinary Medicine openFDA Animal & Veterinary Adverse Events (CVM AER) · 2025

Every figure on PlainBreed is rendered directly from FDA openFDA adverse event data, no number is typed in by an editor. This page draws directly on FDA openFDA data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.