Unable to stand after Ivermectin (Heartgard) in dogs

The FDA has received 67 reports of unable to stand in dogs after Ivermectin. That is 0.6% of all reports for this medicine, compared with 0.3% across reports for all dog medicines, so it is reported unusually often with this medicine.

67Reports

63%Marked serious

54%Recovered

12%Died or euthanised

37 daysTypical onset

How soon it started

Same day

7 14%

1–2 days

4 8.2%

3–7 days

2 4.1%

1–4 weeks

8 16%

Over a month

28 57%

How the animals did

Recovered

29 43%

Recovered with lasting effects

7 10%

Still unwell when reported

9 13%

Died

3 4.5%

Euthanised

5 7.5%

Not known

14 21%

Problems reported at the same time

23 34%

19 28%

18 27%

14 21%

13 19%

13 19%

Eye or vision problems

12 18%

Weakness

11 16%

Age of the animals

Under 1 year

1–3 years

4–7 years

8–11 years

12+ years

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 unable to stand in dogs?: 67 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 37 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).

Unable to stand with similar medicines

Unable to stand after Ivermectin + Pyrantel (Heartgard Plus) 198 reports · 0.1% of its reports
Unable to stand after Milbemycin Oxime + Spinosad (Trifexis) 419 reports · 0.3% of its reports
Unable to stand after Moxidectin (ProHeart 6) 132 reports · 0.3% of its reports
Unable to stand after Milbemycin Oxime + Praziquantel (Interceptor Plus) 76 reports · 0.2% of its reports
Unable to stand after Milbemycin Oxime (Interceptor) 28 reports · 0.1% of its reports
Unable to stand after Selamectin (Revolution) 39 reports · 0.1% of its reports

All reported side effects of Ivermectin in dogs · Medicines most reported with unable to stand