Loose stool after Moxidectin (ProHeart 6) in dogs

The FDA has received 332 reports of loose stool in dogs after Moxidectin. That is 0.7% of all reports for this medicine, compared with 0.9% across reports for all dog medicines.

332Reports

40%Marked serious

20%Recovered

7.8%Died or euthanised

1 daysTypical onset

How soon it started

Same day

126 48%

1–2 days

54 21%

3–7 days

31 12%

1–4 weeks

27 10%

Over a month

25 9.5%

How the animals did

Recovered

67 20%

Still unwell when reported

169 51%

Died

17 5.1%

Euthanised

9 2.7%

Not known

70 21%

Problems reported at the same time

199 60%

124 37%

103 31%

72 22%

57 17%

42 13%

40 12%

34 10%

Age of the animals

Under 1 year

1–3 years

135

4–7 years

8–11 years

12+ years

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 loose stool in dogs?: 332 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 1 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).

Loose stool with similar medicines

Loose stool after Ivermectin + Pyrantel (Heartgard Plus) 1,339 reports · 0.9% of its reports
Loose stool after Milbemycin Oxime + Spinosad (Trifexis) 885 reports · 0.7% of its reports
Loose stool after Milbemycin Oxime + Praziquantel (Interceptor Plus) 406 reports · 1.3% of its reports
Loose stool after Milbemycin Oxime (Interceptor) 327 reports · 1.1% of its reports
Loose stool after Selamectin (Revolution) 156 reports · 0.5% of its reports
Loose stool after Ivermectin (Heartgard) 88 reports · 0.7% of its reports
Loose stool after Ivermectin + Praziquantel + Pyrantel (Iverhart Max) 120 reports · 1.4% of its reports

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