Ivermectin + Pyrantel (Heartgard Plus) side effects in cats
66 reports sent to the FDA between 2001 and 2025 involve Ivermectin + Pyrantel in cats. The most reported problems were accidental exposure, vomiting, lethargy. 20% were marked serious.
About this medicine
Ivermectin prevents heartworm disease (monthly). Pyrantel treats roundworms and hookworms.
Products with this combination include Heartgard Plus, Tri-Heart Plus, Iverhart Plus. 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.
How soon problems started
Time from the first dose to the first sign, where both dates were reported (27 reports).
How the animals did
Breeds named most often
Popular breeds appear more often because there are more of them.
- Domestic 25 reports
- Domestic Shorthair 13 reports
- Siamese 2 reports
- Persian 2 reports
- Himalayan 1 reports
- American Shorthair 1 reports
- Domestic Longhair 1 reports
- Maine Coon 1 reports
- Cat (other) 1 reports