Pyrimethamine — 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. Pyrimethamine is a active ingredient.
Total reports
Pyrimethamine: 28
Reports by species (top entries)
- Horse 22
- Cat 2
Top reported reactions (VEDDRA terms, top entries)
- Lethargy (see also Central nervous system depression in 'Neurological') 6
- Leucopenia NOS 4
- Anorexia 3
- Ataxia 3
- Death by euthanasia 3
- Decreased appetite 3
- Diarrhoea 3
- Neutropenia 3
- Potency, Low 3
- Death 2
Source JSON: pdf-raw/ade/ade_active_ingredients_2026-07-22_b26.json (openFDA animalandveterinary/event.json, pulled 2026-07-22).