4% Deltamethrin
50 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 | 50 |
| Reports involving death | 0 |
| Case-fatality rate (reported events) | 0.0% |
| Distinct species in reports | 1 |
| 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.
4% Deltamethrin Adverse Event Insights
The FDA Center for Veterinary Medicine database currently holds 50 adverse event reports referencing 4% Deltamethrin, including 0 reports in which the animal died — a 0.0% case-fatality figure among reported events only, not a population-level mortality rate. Active ingredient on file: 4% Deltamethrin. Reported administration routes include Unknown, Topical, Cutaneous, Other. 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 4% Deltamethrin reports are Dog (50 reports), with Dog accounting for the largest share. Within those species, Retriever - Labrador (7), Poodle (unspecified) (3), Shih Tzu (3) 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 4% Deltamethrin are Emesis (17), Lack of efficacy - NOS (10), Lack of efficacy (ectoparasite) - flea (5), Hyperactivity (5). Of the 50 reports with a coded outcome, Recovered/Normal is the leading category at 52.0%. 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 4% Deltamethrin.
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.