Heart murmur after Moxidectin (ProHeart 6) in dogs

75 reports to the FDA describe heart murmur in dogs given Moxidectin. That is 0.1% of all reports for this medicine, compared with 0.2% across reports for all dog medicines.

75Reports

68%Marked serious

9.3%Recovered

28%Died or euthanised

5 daysTypical onset

How soon it started

Same day

16 26%

1–2 days

9 15%

3–7 days

7 11%

1–4 weeks

9 15%

Over a month

20 33%

How the animals did

Recovered

6 8.0%

Recovered with lasting effects

1 1.3%

Still unwell when reported

43 57%

Died

13 17%

Euthanised

8 11%

Not known

4 5.3%

Problems reported at the same time

30 40%

23 31%

22 29%

21 28%

21 28%

19 25%

16 21%

12 16%

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 heart murmur in dogs?: 75 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 5 days 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).

Heart murmur with similar medicines

Heart murmur after Ivermectin + Pyrantel (Heartgard Plus) 109 reports · 0.1% of its reports
Heart murmur after Milbemycin Oxime + Spinosad (Trifexis) 327 reports · 0.3% of its reports
Heart murmur after Milbemycin Oxime + Praziquantel (Interceptor Plus) 95 reports · 0.3% of its reports
Heart murmur after Milbemycin Oxime (Interceptor) 32 reports · 0.1% of its reports
Heart murmur after Ivermectin (Heartgard) 32 reports · 0.3% of its reports

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