Ivermectin

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11,677 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.
11,677
Total Reports
626
Deaths Reported
540.0%
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%)

Data Summary

Metric Value
Total adverse event reports 11,677
Reports involving death 626
Case-fatality rate (reported events) 540.0%
Distinct species in reports 10
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.

Ivermectin Adverse Event Insights

The FDA Center for Veterinary Medicine database currently holds 11,677 adverse event reports referencing Ivermectin, including 626 reports in which the animal died — a 540.0% case-fatality figure among reported events only, not a population-level mortality rate. Active ingredient on file: Ivermectin. Reported administration routes include Oral, Unknown, Topical, Subcutaneous. 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 Ivermectin reports are Dog (9,322 reports), Unknown (759 reports), Cattle (677 reports), with Dog accounting for the largest share. Within those species, Retriever - Labrador (1,293), Unknown (1,049), Crossbred Canine/dog (565) 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 Ivermectin are Lack of efficacy (endoparasite) - heartworm (1,739), Emesis (1,470), Vomiting (1,369), INEFFECTIVE, HEARTWORM LARVAE (966). Of the 10,149 reports with a coded outcome, Recovered/Normal is the leading category at 34.2%. 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 Ivermectin.

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