Death after Ivermectin (Heartgard) in dogs

The FDA has received 609 reports of death in dogs after Ivermectin. That is 5.1% of all reports for this medicine, compared with 5.2% across reports for all dog medicines.

609Reports

56%Marked serious

0.3%Recovered

98%Died or euthanised

31 daysTypical onset

How soon it started

Same day

39 18%

1–2 days

24 11%

3–7 days

14 6.5%

1–4 weeks

26 12%

Over a month

111 52%

How the animals did

Recovered with lasting effects

2 0.3%

Still unwell when reported

1 0.2%

Died

420 69%

Euthanised

178 29%

Not known

8 1.3%

Problems reported at the same time

149 24%

129 21%

119 20%

107 18%

102 17%

97 16%

Eye or vision problems

74 12%

Breathing problems

74 12%

Age of the animals

Under 1 year

111

1–3 years

4–7 years

129

8–11 years

113

12+ years

104

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 death in dogs?: 609 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 31 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).

Death with similar medicines

Death after Ivermectin + Pyrantel (Heartgard Plus) 2,810 reports · 1.9% of its reports
Death after Milbemycin Oxime + Spinosad (Trifexis) 3,307 reports · 2.5% of its reports
Death after Moxidectin (ProHeart 6) 2,447 reports · 4.8% of its reports
Death after Milbemycin Oxime + Praziquantel (Interceptor Plus) 920 reports · 2.9% of its reports
Death after Milbemycin Oxime (Interceptor) 1,015 reports · 3.4% of its reports
Death after Selamectin (Revolution) 785 reports · 2.7% of its reports
Death after Ivermectin + Praziquantel + Pyrantel (Iverhart Max) 125 reports · 1.5% of its reports
Death after Moxidectin + Pyrantel + Sarolaner (Simparica Trio) 60 reports · 5.2% of its reports

All reported side effects of Ivermectin in dogs · Medicines most reported with death