Drug profile

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

419 FDA reports name Fipronil 9.8%/S-Methoprene 8.8%/ Amitraz 22.1% Spot-On, a high-volume drug in the CVM extract. Species, reactions, and outcomes follow.

#345 of 2,679
by report volume (all drugs)
419
adverse-event reports
0.7%
death-coded share
Dog
most-reported species

Corpus placement

According to the FDA Center for Veterinary Medicine openFDA adverse-event extract, Fipronil 9.8%/S-Methoprene 8.8%/ Amitraz 22.1% Spot-On ranks #345 of 2679 by total reports (419) and #1088 of 1130 by death-coded share (0.7%). 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)
#345
This drug, reports of 2679
#1088
This drug, death share of 1130

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 9.8%/S-Methoprene 8.8%/ Amitraz 22.1% Spot-On has 419 reports now versus 419 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 9.8%/S-Methoprene 8.8%/ Amitraz 22.1% Spot-On changes

Signature read: 419 reports place Fipronil 9.8%/S-Methoprene 8.8%/ Amitraz 22.1% Spot-On in the upper third of FDA AER volume (#345 of 2,679).

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-coded share of reports

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: 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.

High-volume nationwide drug peers

Two openFDA-derived peer sets for Fipronil 9.8%/S-Methoprene 8.8%/ Amitraz 22.1% Spot-On, both floored at ≥50 reports so the neighborhoods stay in the advertised mass.

What to do with this drug

  • Compare Fipronil 9.8%/S-Methoprene 8.8%/ Amitraz 22.1% Spot-On's report volume and death-coded share against similar drugs nationwide. See similar drugs
  • Read how death-coded share differs from a mortality rate before drawing conclusions. Understanding adverse events
  • Browse the full drug directory to compare report counts across products. All drugs

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 9.8%/S-Methoprene 8.8%/ Amitraz 22.1% Spot-On (#345 of 2,679 by report volume); death-coded 0.7%. PlainBreed drug row · report volume stamp 419 · 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 →