Drug profile

The FDA adverse-event record for Milbemycin, Lufenuron

2,328 adverse-event reports submitted to the FDA Center for Veterinary Medicine reference Milbemycin, Lufenuron. See the species affected, top reactions, and outcomes below.

2,328
adverse-event reports
1.5%
death-coded share
Dog
most-reported species
757
INEFFECTIVE, HEARTWORM LARVAE - 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.
2,328
Total Reports
35
Deaths Reported
1.5%
Death Rate

Active Ingredients

Milbemycin, Lufenuron

Administration Routes

OralUnknownTopicalOphthalmic

Species Affected

Dog 2,207
Unknown 108
Human 9
Cat 3
Other 1

Most Affected Breeds

Crossbred Canine/dog 537
Retriever - Labrador 283
Unknown 118
Retriever - Golden 88
Shepherd Dog - German 81
Terrier - Yorkshire 60
Chihuahua 59
Dog (unknown) 56
Shih Tzu 55
Beagle 55

Most Reported Reactions

INEFFECTIVE, HEARTWORM LARVAE 757
Vomiting 446
INEFFECTIVE, ASCARIDS NOS 233
Lack of efficacy (endoparasite) - hookworm 227
Diarrhoea 212
Depression 202
Lack of efficacy (endoparasite) - whipworm 124
Pruritus 116
Anorexia 115
Convulsion 73
Underfilling, Package 55
Ataxia 42

Outcome Breakdown

Died
35 (87.5%)
Ongoing
5 (12.5%)

Milbemycin, Lufenuron Adverse Event Insights

2,328 reports name Milbemycin, Lufenuron; 35 recorded a death outcome (1.5% of reported events, not a population-level mortality rate). Active ingredient: Milbemycin, Lufenuron. Administration routes: Oral, Unknown, Topical, Ophthalmic.

By species: Dog (2,207 reports), Unknown (108 reports), Human (9 reports). By breed: Crossbred Canine/dog (537), Retriever - Labrador (283), Unknown (118).

Leading clinical signs: INEFFECTIVE, HEARTWORM LARVAE (757), Vomiting (446), INEFFECTIVE, ASCARIDS NOS (233), Lack of efficacy (endoparasite) - hookworm (227). Outcome, 40 coded reports: Died leads at 87.5%.

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.