Selamectin (Revolution) side effects in cats
21,959 reports sent to the FDA between 1999 and 2026 involve Selamectin in cats. The most reported problems were hair loss, application site reaction, lethargy. 7.9% were marked serious, and where it was recorded, signs eased after stopping the medicine in 82% of cases.
About this medicine
Selamectin prevents heartworm and treats fleas, ear mites and some worms (spot-on).
Products with this ingredient include Revolution. The FDA hides brand names in its public data, so these reports cover every product with the same active ingredients.
Some herding breeds (for example Collies) carry the MDR1 gene variant and can be more sensitive to this drug class at high doses.
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 (9,528 reports).
How the animals did
Breeds named most often
Popular breeds appear more often because there are more of them.
- Domestic 8,313 reports
- Domestic Shorthair 6,438 reports
- Cat (other) 1,051 reports
- Domestic Longhair 820 reports
- Domestic Mediumhair 605 reports
- Siamese 467 reports
- Maine Coon 325 reports
- Persian 280 reports
- Bengal 173 reports
- Ragdoll 158 reports