Weakness after Moxidectin (ProHeart 6) in dogs

913 reports to the FDA describe weakness in dogs given Moxidectin. That is 1.8% of all reports for this medicine, compared with 1.4% across reports for all dog medicines.

913Reports

55%Marked serious

24%Recovered

19%Died or euthanised

Same dayTypical onset

How soon it started

Same day

429 66%

1–2 days

66 10%

3–7 days

51 7.9%

1–4 weeks

52 8.0%

Over a month

49 7.6%

How the animals did

Recovered

215 24%

Still unwell when reported

326 36%

Died

107 12%

Euthanised

67 7.3%

Not known

198 22%

Problems reported at the same time

472 52%

389 43%

344 38%

252 28%

206 23%

176 19%

165 18%

156 17%

Age of the animals

Under 1 year

1–3 years

350

4–7 years

240

8–11 years

171

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 weakness in dogs?: 913 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).

Weakness with similar medicines

Weakness after Ivermectin + Pyrantel (Heartgard Plus) 453 reports · 0.3% of its reports
Weakness after Milbemycin Oxime + Spinosad (Trifexis) 847 reports · 0.7% of its reports
Weakness after Milbemycin Oxime + Praziquantel (Interceptor Plus) 256 reports · 0.8% of its reports
Weakness after Milbemycin Oxime (Interceptor) 223 reports · 0.7% of its reports
Weakness after Selamectin (Revolution) 214 reports · 0.7% of its reports
Weakness after Ivermectin (Heartgard) 229 reports · 1.9% of its reports
Weakness after Ivermectin + Praziquantel + Pyrantel (Iverhart Max) 76 reports · 0.9% of its reports

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