Nystagmus after Moxidectin (ProHeart 6) in dogs

105 reports to the FDA describe nystagmus in dogs given Moxidectin. That is 0.2% of all reports for this medicine, compared with 0.3% across reports for all dog medicines.

105Reports

44%Marked serious

10%Recovered

29%Died or euthanised

Same dayTypical onset

How soon it started

Same day

29 53%

1–2 days

13 24%

3–7 days

9 16%

1–4 weeks

2 3.6%

Over a month

2 3.6%

How the animals did

Recovered

11 10%

Still unwell when reported

33 31%

Died

22 21%

Euthanised

8 7.6%

Not known

31 30%

Problems reported at the same time

51 49%

34 32%

31 30%

30 29%

29 28%

23 22%

18 17%

16 15%

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 nystagmus in dogs?: 105 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).

Nystagmus with similar medicines

Nystagmus after Ivermectin + Pyrantel (Heartgard Plus) 88 reports · 0.1% of its reports
Nystagmus after Milbemycin Oxime + Spinosad (Trifexis) 122 reports · 0.1% of its reports
Nystagmus after Milbemycin Oxime + Praziquantel (Interceptor Plus) 41 reports · 0.1% of its reports
Nystagmus after Milbemycin Oxime (Interceptor) 42 reports · 0.1% of its reports
Nystagmus after Selamectin (Revolution) 52 reports · 0.2% of its reports
Nystagmus after Ivermectin (Heartgard) 48 reports · 0.4% of its reports

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