Systemic disorder after Ivermectin (Heartgard) in dogs

32 reports to the FDA describe systemic disorder in dogs given Ivermectin. That is 0.3% of all reports for this medicine, compared with 0.2% across reports for all dog medicines.

32Reports

63%Marked serious

31%Recovered

19%Died or euthanised

36 daysTypical onset

How soon it started

Same day

1 6.3%

1–2 days

1 6.3%

3–7 days

1 6.3%

1–4 weeks

4 25%

Over a month

9 56%

How the animals did

Recovered

5 16%

Recovered with lasting effects

5 16%

Still unwell when reported

5 16%

Died

3 9.4%

Euthanised

3 9.4%

Not known

11 34%

Problems reported at the same time

11 34%

9 28%

7 22%

6 19%

6 19%

6 19%

6 19%

5 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 systemic disorder in dogs?: 32 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 36 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).

Systemic disorder with similar medicines

Systemic disorder after Ivermectin + Pyrantel (Heartgard Plus) 136 reports · 0.1% of its reports
Systemic disorder after Milbemycin Oxime + Spinosad (Trifexis) 404 reports · 0.3% of its reports
Systemic disorder after Moxidectin (ProHeart 6) 123 reports · 0.2% of its reports
Systemic disorder after Milbemycin Oxime + Praziquantel (Interceptor Plus) 21 reports · 0.1% of its reports
Systemic disorder after Milbemycin Oxime (Interceptor) 26 reports · 0.1% of its reports
Systemic disorder after Selamectin (Revolution) 76 reports · 0.3% of its reports

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