Digestive tract disorder after Ivermectin (Heartgard) in dogs

63 reports to the FDA describe digestive tract disorder in dogs given Ivermectin. That is 0.5% of all reports for this medicine, compared with 2.0% across reports for all dog medicines, so it is reported less often than average with this medicine.

63Reports

48%Marked serious

11%Recovered

22%Died or euthanised

30 daysTypical onset

How soon it started

Same day

9 24%

1–2 days

4 11%

3–7 days

1 2.6%

1–4 weeks

6 16%

Over a month

18 47%

How the animals did

Recovered

3 4.8%

Recovered with lasting effects

4 6.3%

Still unwell when reported

8 13%

Died

7 11%

Euthanised

7 11%

Not known

34 54%

Problems reported at the same time

21 33%

21 33%

17 27%

16 25%

13 21%

12 19%

11 17%

7 11%

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 digestive tract disorder in dogs?: 63 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 30 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).

Digestive tract disorder with similar medicines

Digestive tract disorder after Ivermectin + Pyrantel (Heartgard Plus) 16,532 reports · 11% of its reports
Digestive tract disorder after Milbemycin Oxime + Spinosad (Trifexis) 487 reports · 0.4% of its reports
Digestive tract disorder after Moxidectin (ProHeart 6) 88 reports · 0.2% of its reports
Digestive tract disorder after Milbemycin Oxime + Praziquantel (Interceptor Plus) 123 reports · 0.4% of its reports
Digestive tract disorder after Milbemycin Oxime (Interceptor) 178 reports · 0.6% of its reports
Digestive tract disorder after Selamectin (Revolution) 75 reports · 0.3% of its reports
Digestive tract disorder after Ivermectin + Praziquantel + Pyrantel (Iverhart Max) 61 reports · 0.7% of its reports

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