Diarrhea after Moxidectin (ProHeart 6) in dogs

The FDA has received 4,291 reports of diarrhea in dogs after Moxidectin. That is 8.5% of all reports for this medicine, compared with 8.4% across reports for all dog medicines.

4,291Reports

46%Marked serious

22%Recovered

8.0%Died or euthanised

Same dayTypical onset

How soon it started

Same day

1,986 63%

1–2 days

623 20%

3–7 days

230 7.3%

1–4 weeks

141 4.5%

Over a month

180 5.7%

How the animals did

Recovered

934 22%

Recovered with lasting effects

2 0.0%

Still unwell when reported

1,927 45%

Died

246 5.7%

Euthanised

98 2.3%

Not known

1,084 25%

Problems reported at the same time

3,009 70%

1,377 32%

1,266 30%

894 21%

550 13%

482 11%

386 9.0%

362 8.4%

Age of the animals

Under 1 year

378

1–3 years

1,938

4–7 years

1,123

8–11 years

555

12+ years

222

About this medicine

Moxidectin prevents heartworm disease (monthly topical, or a 6- or 12-month injection for dogs).

Products with this ingredient include ProHeart 6, ProHeart 12. 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 Moxidectin cause diarrhea in dogs?: 4,291 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 the same day 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).

Diarrhea with similar medicines

Diarrhea after Ivermectin + Pyrantel (Heartgard Plus) 9,076 reports · 6.1% of its reports
Diarrhea after Milbemycin Oxime + Spinosad (Trifexis) 7,183 reports · 5.5% of its reports
Diarrhea after Milbemycin Oxime + Praziquantel (Interceptor Plus) 2,695 reports · 8.5% of its reports
Diarrhea after Milbemycin Oxime (Interceptor) 2,873 reports · 9.7% of its reports
Diarrhea after Selamectin (Revolution) 1,974 reports · 6.7% of its reports
Diarrhea after Ivermectin (Heartgard) 693 reports · 5.8% of its reports
Diarrhea after Ivermectin + Praziquantel + Pyrantel (Iverhart Max) 954 reports · 11% of its reports
Diarrhea after Moxidectin + Pyrantel + Sarolaner (Simparica Trio) 125 reports · 11% of its reports

All reported side effects of Moxidectin in dogs · Medicines most reported with diarrhea