Hind limb paresis after Moxidectin (ProHeart 6) in dogs

The FDA has received 173 reports of hind limb paresis in dogs after Moxidectin. That is 0.3% of all reports for this medicine, compared with 0.3% across reports for all dog medicines.

173Reports

40%Marked serious

8.1%Recovered

21%Died or euthanised

1 daysTypical onset

How soon it started

Same day

37 41%

1–2 days

19 21%

3–7 days

12 13%

1–4 weeks

12 13%

Over a month

10 11%

How the animals did

Recovered

13 7.5%

Recovered with lasting effects

1 0.6%

Still unwell when reported

62 36%

Died

30 17%

Euthanised

7 4.0%

Not known

60 35%

Problems reported at the same time

51 29%

46 27%

39 23%

37 21%

28 16%

27 16%

27 16%

23 13%

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 hind limb paresis in dogs?: 173 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).

Hind limb paresis with similar medicines

Hind limb paresis after Ivermectin + Pyrantel (Heartgard Plus) 151 reports · 0.1% of its reports
Hind limb paresis after Milbemycin Oxime + Spinosad (Trifexis) 91 reports · 0.1% of its reports
Hind limb paresis after Milbemycin Oxime + Praziquantel (Interceptor Plus) 26 reports · 0.1% of its reports
Hind limb paresis after Milbemycin Oxime (Interceptor) 50 reports · 0.2% of its reports
Hind limb paresis after Selamectin (Revolution) 65 reports · 0.2% of its reports
Hind limb paresis after Ivermectin (Heartgard) 49 reports · 0.4% of its reports

All reported side effects of Moxidectin in dogs · Medicines most reported with hind limb paresis