Abnormal ultrasound finding after Moxidectin (ProHeart 6) in dogs

The FDA has received 268 reports of abnormal ultrasound finding in dogs after Moxidectin. That is 0.5% of all reports for this medicine, compared with 0.5% across reports for all dog medicines.

268Reports

58%Marked serious

7.8%Recovered

37%Died or euthanised

1 daysTypical onset

How soon it started

Same day

70 43%

1–2 days

28 17%

3–7 days

19 12%

1–4 weeks

17 11%

Over a month

27 17%

How the animals did

Recovered

21 7.8%

Still unwell when reported

100 37%

Died

58 22%

Euthanised

40 15%

Not known

49 18%

Problems reported at the same time

142 53%

138 51%

126 47%

122 46%

98 37%

87 32%

73 27%

67 25%

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 abnormal ultrasound finding in dogs?: 268 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).

Abnormal ultrasound finding with similar medicines

Abnormal ultrasound finding after Ivermectin + Pyrantel (Heartgard Plus) 203 reports · 0.1% of its reports
Abnormal ultrasound finding after Milbemycin Oxime + Spinosad (Trifexis) 240 reports · 0.2% of its reports
Abnormal ultrasound finding after Milbemycin Oxime + Praziquantel (Interceptor Plus) 67 reports · 0.2% of its reports
Abnormal ultrasound finding after Milbemycin Oxime (Interceptor) 59 reports · 0.2% of its reports
Abnormal ultrasound finding after Selamectin (Revolution) 40 reports · 0.1% of its reports
Abnormal ultrasound finding after Ivermectin (Heartgard) 57 reports · 0.5% of its reports

All reported side effects of Moxidectin in dogs · Medicines most reported with abnormal ultrasound finding