Fenbendazole — 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. Fenbendazole is a veterinary active ingredient.
Total reports
Fenbendazole: 4249
Reports by species (top entries)
- Dog 3385
- Cattle 204
- Cat 155
- Horse 98
- Human 51
- Goat 43
Top reported reactions (VEDDRA terms, top entries)
- Vomiting 1164
- Diarrhoea 650
- Anorexia 557
- Depression 540
- Death 465
- Lack of efficacy (endoparasite) - hookworm 312
- Lack of efficacy (endoparasite) - tapeworm 154
- Other abnormal test result NOS 143
- INEFFECTIVE, HOOKS 132
- Lethargy (see also Central nervous system depression in 'Neurological') 130
"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).