Butorphanol — 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 2026-07-22. Counts are report-level: one report may list multiple reactions and multiple animals, so figures are not additive and do not imply causation. Butorphanol is a active ingredient.
Total reports
Butorphanol: 3858
Reports by species (top entries)
- Dog 2460
- Cat 1275
- Horse 98
- Other 4
- Other Equids 3
- Human 2
Top reported reactions (VEDDRA terms, top entries)
- Lack of efficacy - NOS 501
- Death 402
- Vomiting 396
- Lethargy (see also Central nervous system depression in 'Neurological') 297
- Diarrhoea 266
- Anorexia 256
- Lethargy (see also Central nervous system depression in Neurological) 241
- Not eating 241
- Bradycardia 236
- Death by euthanasia 222
Source JSON: pdf-raw/ade/ade_active_ingredients_2026-07-22_b9.json (openFDA animalandveterinary/event.json, pulled 2026-07-22).