Lateral recumbency after Ivermectin (Heartgard) in dogs

The FDA has received 46 reports of lateral recumbency in dogs after Ivermectin. That is 0.4% 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.

46Reports

93%Marked serious

33%Recovered

30%Died or euthanised

49 daysTypical onset

How soon it started

Same day

3 10%

1–2 days

2 6.9%

3–7 days

1 3.4%

1–4 weeks

7 24%

Over a month

16 55%

How the animals did

Recovered

9 20%

Recovered with lasting effects

6 13%

Still unwell when reported

8 17%

Died

2 4.3%

Euthanised

12 26%

Not known

9 20%

Problems reported at the same time

20 43%

18 39%

15 33%

15 33%

13 28%

13 28%

12 26%

10 22%

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 lateral recumbency in dogs?: 46 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 49 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).

Lateral recumbency with similar medicines

Lateral recumbency after Ivermectin + Pyrantel (Heartgard Plus) 186 reports · 0.1% of its reports
Lateral recumbency after Milbemycin Oxime + Spinosad (Trifexis) 178 reports · 0.1% of its reports
Lateral recumbency after Moxidectin (ProHeart 6) 358 reports · 0.7% of its reports
Lateral recumbency after Milbemycin Oxime + Praziquantel (Interceptor Plus) 33 reports · 0.1% of its reports
Lateral recumbency after Selamectin (Revolution) 21 reports · 0.1% of its reports

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