Metronidazole — 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. Metronidazole is a veterinary active ingredient.
Total reports
Metronidazole: 3583
Reports by species (top entries)
- Dog 2980
- Cat 386
- Horse 10
- Human 4
- Ferret 2
- Chinchilla 1
Top reported reactions (VEDDRA terms, top entries)
- Diarrhoea 982
- Vomiting 901
- Lethargy (see also Central nervous system depression in 'Neurological') 563
- Anorexia 406
- Other abnormal test result NOS 393
- Death by euthanasia 381
- Elevated alanine aminotransferase (ALT) 352
- Weight loss 316
- Not eating 311
- Bloody diarrhoea 295
"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).