Neurological signs after Moxidectin (ProHeart 6) in dogs

The FDA has received 139 reports of neurological signs in dogs after Moxidectin. That is 0.3% of all reports for this medicine, compared with 0.3% across reports for all dog medicines.

139Reports

31%Marked serious

10%Recovered

24%Died or euthanised

3 daysTypical onset

How soon it started

Same day

24 34%

1–2 days

11 16%

3–7 days

11 16%

1–4 weeks

11 16%

Over a month

13 19%

How the animals did

Recovered

13 9.4%

Recovered with lasting effects

1 0.7%

Still unwell when reported

41 29%

Died

24 17%

Euthanised

10 7.2%

Not known

50 36%

Problems reported at the same time

35 25%

35 25%

34 24%

31 22%

22 16%

21 15%

21 15%

19 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 neurological signs in dogs?: 139 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 3 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).

Neurological signs with similar medicines

Neurological signs after Ivermectin + Pyrantel (Heartgard Plus) 165 reports · 0.1% of its reports
Neurological signs after Milbemycin Oxime + Spinosad (Trifexis) 325 reports · 0.3% of its reports
Neurological signs after Milbemycin Oxime + Praziquantel (Interceptor Plus) 41 reports · 0.1% of its reports
Neurological signs after Milbemycin Oxime (Interceptor) 39 reports · 0.1% of its reports
Neurological signs after Selamectin (Revolution) 69 reports · 0.2% of its reports
Neurological signs after Ivermectin (Heartgard) 86 reports · 0.7% of its reports

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