Thiamazole — 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. Thiamazole is a active ingredient.
Total reports
Thiamazole: 610
Reports by species (top entries)
- Cat 548
- Human 18
- Dog 2
Top reported reactions (VEDDRA terms, top entries)
- Vomiting 146
- Weight loss 98
- Lethargy (see also Central nervous system depression in 'Neurological') 63
- Elevated alanine aminotransferase (ALT) 61
- Anorexia 49
- Decreased appetite 44
- Lack of efficacy - NOS 44
- Excoriation 38
- Other abnormal test result NOS 36
- Pruritus 31
Source JSON: pdf-raw/ade/ade_active_ingredients_2026-07-22_b13.json (openFDA animalandveterinary/event.json, pulled 2026-07-22).