Tremors after Moxidectin (ProHeart 6) in dogs

1,208 reports to the FDA describe tremors in dogs given Moxidectin. That is 2.4% of all reports for this medicine, compared with 3.4% across reports for all dog medicines.

1,208Reports

41%Marked serious

21%Recovered

8.7%Died or euthanised

Same dayTypical onset

How soon it started

Same day

475 56%

1–2 days

164 19%

3–7 days

78 9.2%

1–4 weeks

50 5.9%

Over a month

80 9.4%

How the animals did

Recovered

243 20%

Recovered with lasting effects

5 0.4%

Still unwell when reported

499 41%

Died

72 6.0%

Euthanised

33 2.7%

Not known

356 29%

Problems reported at the same time

401 33%

386 32%

272 23%

189 16%

182 15%

179 15%

148 12%

145 12%

Age of the animals

Under 1 year

1–3 years

470

4–7 years

319

8–11 years

190

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 tremors in dogs?: 1,208 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).

Tremors with similar medicines

Tremors after Ivermectin + Pyrantel (Heartgard Plus) 2,169 reports · 1.5% of its reports
Tremors after Milbemycin Oxime + Spinosad (Trifexis) 5,684 reports · 4.4% of its reports
Tremors after Milbemycin Oxime + Praziquantel (Interceptor Plus) 766 reports · 2.4% of its reports
Tremors after Milbemycin Oxime (Interceptor) 729 reports · 2.4% of its reports
Tremors after Selamectin (Revolution) 984 reports · 3.3% of its reports
Tremors after Ivermectin (Heartgard) 959 reports · 8.0% of its reports
Tremors after Ivermectin + Praziquantel + Pyrantel (Iverhart Max) 245 reports · 2.9% of its reports
Tremors after Moxidectin + Pyrantel + Sarolaner (Simparica Trio) 56 reports · 4.8% of its reports
Tremors after Ivermectin + Praziquantel 61 reports · 30% of its reports
Tremors after Moxidectin + Praziquantel 27 reports · 36% of its reports

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