afoxolaner — 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. afoxolaner is a isoxazoline ectoparasiticide (flea/tick).
Total reports
afoxolaner: 69037
Reports by species (top entries)
- Dog 63981
- Human 92
- Cat 82
- Other 3
- Other Canids 3
- 2
Top reported reactions (VEDDRA terms, top entries)
- Vomiting 15987
- Diarrhoea 6128
- Lethargy (see also Central nervous system depression in 'Neurological') 5710
- Lack of efficacy (ectoparasite) - tick NOS 4991
- Lack of efficacy (ectoparasite) - flea 4532
- Seizure NOS 4406
- Lack of efficacy (bacteria) - Borrelia 3554
- Lack of efficacy (tick) 3389
- Skin disorders NOS 2626
- Lack of efficacy (bacteria) - NOS 2606
"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).