Bradycardia after Ivermectin (Heartgard) in dogs
The FDA has received 49 reports of bradycardia in dogs after Ivermectin. That is 0.4% of all reports for this medicine, compared with 0.3% across reports for all dog medicines.
49Reports
31%Marked serious
8.2%Recovered
37%Died or euthanised
11 daysTypical onset
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How soon it started
How the animals did
Problems reported at the same time
Age of the animals
About this medicine
Ivermectin prevents heartworm disease (monthly).
Products with this ingredient include Heartgard. 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.
Questions owners ask
- Can Ivermectin cause bradycardia in dogs?
- 49 reports link the two, but a report alone does not prove the medicine was the cause: other illnesses, other medicines or coincidence can be involved. Your vet can judge it for your animal.
- How soon after a dose was it reported?
- In half of the reports with dates, it started within 11 days of the first dose.
- What should I do?
- Don't give another dose until you've spoken to your vet, and keep the packaging so you can tell them the product and dose. Your vet can also report it to the FDA (or you can, through the manufacturer or FDA form 1932a).
Bradycardia with similar medicines
- Bradycardia after Ivermectin + Pyrantel (Heartgard Plus) 77 reports · 0.1% of its reports
- Bradycardia after Milbemycin Oxime + Spinosad (Trifexis) 122 reports · 0.1% of its reports
- Bradycardia after Moxidectin (ProHeart 6) 267 reports · 0.5% of its reports
- Bradycardia after Milbemycin Oxime (Interceptor) 31 reports · 0.1% of its reports
- Bradycardia after Selamectin (Revolution) 32 reports · 0.1% of its reports
All reported side effects of Ivermectin in dogs · Medicines most reported with bradycardia