ivermectin — FDA Animal & Veterinary Adverse Event (ADE) Reports
Source: openFDA animalandveterinary/event.json, the FDA Center for Veterinary Medicine (CVM) adverse event report database. Data pulled 2026-07-21. Counts are report-level: one report may list multiple reactions and multiple animals, so figures are not additive and do not imply causation. ivermectin is a macrocyclic lactone (endectocide: heartworm/parasite).
Total reports
ivermectin: 194447
Reports by species (top entries)
- Dog 167897
- Horse 3499
- Cattle 2458
- Cat 1093
- Human 739
- Sheep 250
Top reported reactions (VEDDRA terms, top entries)
- INEFFECTIVE, HEARTWORM LARVAE 37191
- Lack of efficacy (endoparasite) - hookworm 26113
- Lack of efficacy (endoparasite) - heartworm 24396
- Vomiting 23145
- Digestive tract disorder NOS 16792
- INEFFECTIVE, ASCARIDS NOS 11897
- Diarrhoea 10122
- Cardiac disorder NOS 10105
- Lack of efficacy - NOS 8927
- Tablets, Abnormal 8038
"Lack of efficacy" terms denote product-performance reports, not adverse reactions.
Source JSON: pdf-raw/ade/ade_active_ingredients_2026-07-21.json (openFDA animalandveterinary/event.json, pulled 2026-07-21).