Spinosad (Comfortis) side effects in dogs
57,095 reports sent to the FDA between 2007 and 2026 involve Spinosad in dogs. The most reported problems were vomiting, lethargy, itching. 7.7% were marked serious.
About this medicine
Spinosad kills fleas; monthly chewable.
Products with this ingredient include Comfortis. 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 dog 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 (27,635 reports).
How the animals did
Breeds named most often
Popular breeds appear more often because there are more of them.
- Chihuahua 3,150 reports
- Yorkshire Terrier 2,760 reports
- Labrador Retriever 2,451 reports
- Shih Tzu 2,347 reports
- Boxer (german Boxer) 1,412 reports
- Dachshund 1,340 reports
- Poodle 1,268 reports
- German Pomeranian Spitz 1,201 reports
- Dog (other) 1,195 reports
- Pit Bull 1,182 reports