Walking difficulty after Moxidectin (ProHeart 6) in dogs

The FDA has received 147 reports of walking difficulty in dogs after Moxidectin. That is 0.3% of all reports for this medicine, compared with 0.4% across reports for all dog medicines.

147Reports

71%Marked serious

15%Recovered

20%Died or euthanised

Same dayTypical onset

How soon it started

Same day

73 52%

1–2 days

25 18%

3–7 days

13 9.3%

1–4 weeks

13 9.3%

Over a month

16 11%

How the animals did

Recovered

22 15%

Still unwell when reported

83 56%

Died

9 6.1%

Euthanised

21 14%

Not known

12 8.2%

Problems reported at the same time

56 38%

51 35%

44 30%

30 20%

29 20%

28 19%

25 17%

25 17%

Age of the animals

Under 1 year

1–3 years

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 walking difficulty in dogs?: 147 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).

Walking difficulty with similar medicines

Walking difficulty after Ivermectin + Pyrantel (Heartgard Plus) 281 reports · 0.2% of its reports
Walking difficulty after Milbemycin Oxime + Spinosad (Trifexis) 580 reports · 0.4% of its reports
Walking difficulty after Milbemycin Oxime + Praziquantel (Interceptor Plus) 113 reports · 0.4% of its reports
Walking difficulty after Milbemycin Oxime (Interceptor) 34 reports · 0.1% of its reports
Walking difficulty after Selamectin (Revolution) 51 reports · 0.2% of its reports
Walking difficulty after Ivermectin (Heartgard) 70 reports · 0.6% of its reports
Walking difficulty after Ivermectin + Praziquantel + Pyrantel (Iverhart Max) 24 reports · 0.3% of its reports

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