Drug profile

The FDA adverse-event record for Fipronil 9.8%/S-Methoprene 8.8%/ Amitraz 22.1% Spot-On

419 adverse-event reports submitted to the FDA Center for Veterinary Medicine reference Fipronil 9.8%/S-Methoprene 8.8%/ Amitraz 22.1% Spot-On. See the species affected, top reactions, and outcomes below.

419
adverse-event reports
0.7%
death-coded share
Dog
most-reported species
273
Lethargy (see also Central nervous system depression in 'Neurological') - 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.
419
Total Reports
3
Deaths Reported
0.7%
Death Rate

Active Ingredients

Fipronil 9.8%/S-Methoprene 8.8%/ Amitraz 22.1% Spot-On

Administration Routes

UnknownTopical

Species Affected

Dog 417
Other Canids 2

Most Affected Breeds

Retriever - Labrador 71
Dog (other) 45
Siberian Husky 21
Retriever - Golden 21
Crossbred Canine/dog 21
Shepherd Dog - German 20
Shepherd Dog - Australian 13
Collie - Border 13
Sheepdog - Shetland 11
Mixed (Dog) 10

Most Reported Reactions

Lethargy (see also Central nervous system depression in 'Neurological') 273
Vomiting 68
Ataxia 33
Behavioural disorder NOS 30
Diarrhoea 29
Application site irritation 22
Bradycardia 19
Anorexia 18
Application site hair loss 18
Hyperactivity 15
Application site erythema 13
Seizure NOS 13

Outcome Breakdown

Recovered/Normal
208 (49.1%)
Outcome Unknown
195 (46.0%)
Ongoing
18 (4.2%)
Euthanized
2 (0.5%)
Died
1 (0.2%)

Fipronil 9.8%/S-Methoprene 8.8%/ Amitraz 22.1% Spot-On Adverse Event Insights

419 reports name Fipronil 9.8%/S-Methoprene 8.8%/ Amitraz 22.1% Spot-On; 3 recorded a death outcome (0.7% of reported events, not a population-level mortality rate). Active ingredient: Fipronil 9.8%/S-Methoprene 8.8%/ Amitraz 22.1% Spot-On. Administration routes: Unknown, Topical.

By species: Dog (417 reports), Other Canids (2 reports). By breed: Retriever - Labrador (71), Dog (other) (45), Siberian Husky (21).

Leading clinical signs: Lethargy (see also Central nervous system depression in 'Neurological') (273), Vomiting (68), Ataxia (33), Behavioural disorder NOS (30). Outcome, 424 coded reports: Recovered/Normal leads at 49.1%.

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.