Drug profile

The FDA adverse-event record for Lufenuron

545 adverse-event reports submitted to the FDA Center for Veterinary Medicine reference Lufenuron. See the species affected, top reactions, and outcomes below.

545
adverse-event reports
4.8%
death-coded share
Cat
most-reported species
76
Lack of efficacy (ectoparasite) - flea - 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.
545
Total Reports
26
Deaths Reported
4.8%
Death Rate

Active Ingredients

Lufenuron

Administration Routes

SubcutaneousOralUnknownParenteralIntramuscularIntradermalSubconjunctival

Species Affected

Cat 341
Dog 116
Unknown 87
Human 1

Most Affected Breeds

Domestic Shorthair 140
Unknown 88
Domestic (unspecified) 67
Cat (unknown) 58
Domestic Longhair 22
Dog (unknown) 14
Siamese 12
Retriever - Labrador 10
Crossbred Canine/dog 10
Domestic Mediumhair 10

Most Reported Reactions

Lack of efficacy (ectoparasite) - flea 76
Injection site lump 53
Vomiting 51
Anorexia 42
Lethargy (see also Central nervous system depression in 'Neurological') 37
Lack of efficacy (flea) 29
Product syringe issue 28
Depression 28
Diarrhoea 26
Product problem 25
Syringe, Abnormal 24
Pruritus 21

Outcome Breakdown

Outcome Unknown
118 (34.2%)
Ongoing
110 (31.9%)
Recovered/Normal
89 (25.8%)
Died
19 (5.5%)
Euthanized
7 (2.0%)
Recovered with Sequela
2 (0.6%)

Lufenuron Adverse Event Insights

545 reports name Lufenuron; 26 recorded a death outcome (4.8% of reported events, not a population-level mortality rate). Active ingredient: Lufenuron. Administration routes: Subcutaneous, Oral, Unknown, Parenteral.

By species: Cat (341 reports), Dog (116 reports), Unknown (87 reports). By breed: Domestic Shorthair (140), Unknown (88), Domestic (unspecified) (67).

Leading clinical signs: Lack of efficacy (ectoparasite) - flea (76), Injection site lump (53), Vomiting (51), Anorexia (42). Outcome, 345 coded reports: Outcome Unknown leads at 34.2%.

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.