Fipronil + S-methoprene (Frontline Plus) side effects in cats
367 reports sent to the FDA between 2012 and 2026 involve Fipronil + S-methoprene in cats. The most reported problems were itching, vomiting, lethargy. 22% were marked serious.
About this medicine
Fipronil kills fleas and ticks (spot-on).
Products with this combination include Frontline Plus. The FDA hides brand names in its public data, so these reports cover every product with the same active ingredients.
Most reported side effects
Share = percentage of this medicine's reports that mention the problem. One report can list several problems.
Reports that it didn't work
Some reports are about the medicine not working (for example a cat still getting fleas or heartworm), not about a side effect.
How soon problems started
Time from the first dose to the first sign, where both dates were reported (302 reports).
How the animals did
Breeds named most often
Popular breeds appear more often because there are more of them.
- Domestic Shorthair 195 reports
- Domestic Longhair 41 reports
- Domestic Mediumhair 23 reports
- Siamese 8 reports
- Maine Coon 5 reports
- Persian 4 reports
- Himalayan 3 reports
- Ragdoll 3 reports
- Domestic 3 reports
- American Shorthair 2 reports