Breathing problems after Moxidectin (ProHeart 6) in dogs

The FDA has received 2,372 reports of breathing problems in dogs after Moxidectin. That is 4.7% of all reports for this medicine, compared with 2.7% across reports for all dog medicines, so it is reported unusually often with this medicine.

2,372Reports

65%Marked serious

30%Recovered

19%Died or euthanised

Same dayTypical onset

How soon it started

Same day

1,524 78%

1–2 days

163 8.4%

3–7 days

99 5.1%

1–4 weeks

71 3.7%

Over a month

88 4.5%

How the animals did

Recovered

719 30%

Still unwell when reported

902 38%

Died

322 14%

Euthanised

121 5.1%

Not known

308 13%

Problems reported at the same time

1,270 54%

1,113 47%

712 30%

688 29%

440 19%

386 16%

362 15%

356 15%

Age of the animals

Under 1 year

130

1–3 years

1,072

4–7 years

621

8–11 years

371

12+ years

147

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 breathing problems in dogs?: 2,372 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).

Breathing problems with similar medicines

Breathing problems after Ivermectin + Pyrantel (Heartgard Plus) 1,458 reports · 1.0% of its reports
Breathing problems after Milbemycin Oxime + Spinosad (Trifexis) 2,380 reports · 1.8% of its reports
Breathing problems after Milbemycin Oxime + Praziquantel (Interceptor Plus) 556 reports · 1.8% of its reports
Breathing problems after Milbemycin Oxime (Interceptor) 481 reports · 1.6% of its reports
Breathing problems after Selamectin (Revolution) 465 reports · 1.6% of its reports
Breathing problems after Ivermectin (Heartgard) 345 reports · 2.9% of its reports
Breathing problems after Ivermectin + Praziquantel + Pyrantel (Iverhart Max) 231 reports · 2.7% of its reports
Breathing problems after Moxidectin + Pyrantel + Sarolaner (Simparica Trio) 40 reports · 3.4% of its reports

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