Quiet after Moxidectin (ProHeart 6) in dogs

The FDA has received 36 reports of quiet in dogs after Moxidectin. That is 0.1% of all reports for this medicine, compared with 0.1% across reports for all dog medicines.

36Reports

78%Marked serious

25%Recovered

8.3%Died or euthanised

Same dayTypical onset

How soon it started

Same day

21 58%

1–2 days

6 17%

3–7 days

4 11%

1–4 weeks

1 2.8%

Over a month

4 11%

How the animals did

Recovered

9 25%

Still unwell when reported

24 67%

Died

3 8.3%

Problems reported at the same time

25 69%

15 42%

11 31%

11 31%

9 25%

5 14%

5 14%

5 14%

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 quiet in dogs?: 36 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).

Quiet with similar medicines

Quiet after Ivermectin + Pyrantel (Heartgard Plus) 36 reports · 0.0% of its reports
Quiet after Milbemycin Oxime + Praziquantel (Interceptor Plus) 26 reports · 0.1% of its reports

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