Imidacloprid + Pyriproxyfen

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699 adverse event reports submitted to the FDA

Important: Adverse event reports do not establish that a drug caused or contributed to the event. Consult your veterinarian before making treatment decisions.
699
Total Reports
40
Deaths Reported
570.0%
Death Rate

Active Ingredients

ImidaclopridImidacloprid + PyriproxyfenPyriproxyfen

Administration Routes

TopicalUnknownOralOtherIntraocular

Species Affected

Cat 494
Dog 198
Human 5
Rabbit 1
Unknown 1

Most Affected Breeds

Domestic Shorthair 250
Cat (unknown) 89
Domestic Longhair 56
Domestic Mediumhair 39
Pit Bull 20
Terrier - Yorkshire 17
Maine Coon 17
Dog (unknown) 17
Siamese 13
Chihuahua 13

Most Reported Reactions

Lack of efficacy (ectoparasite) - flea 221
Pruritus 214
Behavioural disorder NOS 82
Lethargy (see also Central nervous system depression in 'Neurological') 82
Vomiting 71
Lack of efficacy (endoparasite) - tapeworm 40
Weight loss 37
Application site alopecia 33
Skin lesion NOS 33
Application site pruritus 29
Anorexia 28
Vocalisation 28

Outcome Breakdown

Outcome Unknown
425 (60.9%)
Recovered/Normal
154 (22.1%)
Ongoing
78 (11.2%)
Died
27 (3.9%)
Euthanized
13 (1.9%)
Recovered with Sequela
1 (0.1%)

Data Summary

Metric Value
Total adverse event reports 699
Reports involving death 40
Case-fatality rate (reported events) 570.0%
Distinct species in reports 5
Distinct breeds in reports 20
Distinct reactions reported 20
Active ingredients on file 3

Source: FDA Center for Veterinary Medicine — Adverse Event Reporting (CVM AER). Counts reflect voluntary reports only.

Imidacloprid + Pyriproxyfen Adverse Event Insights

The FDA Center for Veterinary Medicine database currently holds 699 adverse event reports referencing Imidacloprid + Pyriproxyfen, including 40 reports in which the animal died — a 570.0% case-fatality figure among reported events only, not a population-level mortality rate. Active ingredients on file: Imidacloprid, Imidacloprid + Pyriproxyfen, Pyriproxyfen. Reported administration routes include Topical, Unknown, Oral, 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 Imidacloprid + Pyriproxyfen reports are Cat (494 reports), Dog (198 reports), Human (5 reports), with Cat accounting for the largest share. Within those species, Domestic Shorthair (250), Cat (unknown) (89), Domestic Longhair (56) 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 Imidacloprid + Pyriproxyfen are Lack of efficacy (ectoparasite) - flea (221), Pruritus (214), Behavioural disorder NOS (82), Lethargy (see also Central nervous system depression in 'Neurological') (82). Of the 698 reports with a coded outcome, Outcome Unknown is the leading category at 60.9%. 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 Imidacloprid + Pyriproxyfen.

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

Related

Data sourced from official AKC, AVMA, ACVO, and breed-club veterinary references. See our methodology for details. Retrieved and formatted by PlainBreed Editorial