Drug profile

The FDA adverse-event record for Ivermectin

11,677 adverse-event reports submitted to the FDA Center for Veterinary Medicine reference Ivermectin. See the species affected, top reactions, and outcomes below.

11,677
adverse-event reports
5.4%
death-coded share
Dog
most-reported species
1,739
Lack of efficacy (endoparasite) - heartworm - 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.
11,677
Total Reports
626
Deaths Reported
5.4%
Death Rate

Active Ingredients

Ivermectin

Administration Routes

OralUnknownTopicalSubcutaneousOtherAuricular (Otic)ParenteralIntramuscularOphthalmicIntradermal

Species Affected

Dog 9,322
Unknown 759
Cattle 677
Cat 397
Horse 199
Human 178
Sheep 34
Pig 25
Goat 21
Rabbit 9

Most Affected Breeds

Retriever - Labrador 1,293
Unknown 1,049
Crossbred Canine/dog 565
Shepherd Dog - German 418
Chihuahua 356
Retriever - Golden 295
Terrier - Yorkshire 293
Pit Bull 278
Boxer (German Boxer) 273
Shih Tzu 267

Most Reported Reactions

Lack of efficacy (endoparasite) - heartworm 1,739
Emesis 1,470
Vomiting 1,369
INEFFECTIVE, HEARTWORM LARVAE 966
Lethargy (see also Central nervous system depression in 'Neurological') 960
Ataxia 674
Lack of efficacy - NOS 564
Diarrhoea 530
Seizure NOS 460
Lack of efficacy (ectoparasite) - flea 426
Death 372
Other abnormal test result NOS 345

Outcome Breakdown

Recovered/Normal
3,468 (34.2%)
Outcome Unknown
3,068 (30.2%)
Ongoing
2,516 (24.8%)
Recovered with Sequela
455 (4.5%)
Died
439 (4.3%)
Euthanized
203 (2.0%)

Ivermectin Adverse Event Insights

11,677 reports name Ivermectin; 626 recorded a death outcome (5.4% of reported events, not a population-level mortality rate). Active ingredient: Ivermectin. Administration routes: Oral, Unknown, Topical, Subcutaneous.

By species: Dog (9,322 reports), Unknown (759 reports), Cattle (677 reports). By breed: Retriever - Labrador (1,293), Unknown (1,049), Crossbred Canine/dog (565).

Leading clinical signs: Lack of efficacy (endoparasite) - heartworm (1,739), Emesis (1,470), Vomiting (1,369), INEFFECTIVE, HEARTWORM LARVAE (966). Outcome, 10,149 coded reports: Recovered/Normal 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.