Musculoskeletal disorder after Moxidectin (ProHeart 6) in dogs

The FDA has received 127 reports of musculoskeletal disorder in dogs after Moxidectin. That is 0.3% of all reports for this medicine, compared with 0.3% across reports for all dog medicines.

127Reports

39%Marked serious

12%Recovered

20%Died or euthanised

1 daysTypical onset

How soon it started

Same day

30 34%

1–2 days

17 20%

3–7 days

18 21%

1–4 weeks

12 14%

Over a month

10 11%

How the animals did

Recovered

15 12%

Still unwell when reported

55 43%

Died

10 7.9%

Euthanised

16 13%

Not known

31 24%

Problems reported at the same time

51 40%

47 37%

28 22%

27 21%

26 20%

25 20%

Abnormal radiograph finding

20 16%

Behaviour change

19 15%

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 musculoskeletal disorder in dogs?: 127 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).

Musculoskeletal disorder with similar medicines

Musculoskeletal disorder after Ivermectin + Pyrantel (Heartgard Plus) 197 reports · 0.1% of its reports
Musculoskeletal disorder after Milbemycin Oxime + Spinosad (Trifexis) 352 reports · 0.3% of its reports
Musculoskeletal disorder after Milbemycin Oxime + Praziquantel (Interceptor Plus) 92 reports · 0.3% of its reports
Musculoskeletal disorder after Milbemycin Oxime (Interceptor) 60 reports · 0.2% of its reports
Musculoskeletal disorder after Selamectin (Revolution) 61 reports · 0.2% of its reports
Musculoskeletal disorder after Ivermectin (Heartgard) 53 reports · 0.4% of its reports

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