Disorientation after Moxidectin (ProHeart 6) in dogs

The FDA has received 293 reports of disorientation in dogs after Moxidectin. That is 0.6% of all reports for this medicine, compared with 1.0% across reports for all dog medicines, so it is reported less often than average with this medicine.

293Reports

46%Marked serious

19%Recovered

17%Died or euthanised

Same dayTypical onset

How soon it started

Same day

98 52%

1–2 days

28 15%

3–7 days

25 13%

1–4 weeks

15 7.9%

Over a month

23 12%

How the animals did

Recovered

54 18%

Recovered with lasting effects

1 0.3%

Still unwell when reported

95 32%

Died

33 11%

Euthanised

17 5.8%

Not known

93 32%

Problems reported at the same time

95 32%

88 30%

83 28%

64 22%

56 19%

56 19%

52 18%

49 17%

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 disorientation in dogs?: 293 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).

Disorientation with similar medicines

Disorientation after Ivermectin + Pyrantel (Heartgard Plus) 588 reports · 0.4% of its reports
Disorientation after Milbemycin Oxime + Spinosad (Trifexis) 1,317 reports · 1.0% of its reports
Disorientation after Milbemycin Oxime + Praziquantel (Interceptor Plus) 183 reports · 0.6% of its reports
Disorientation after Milbemycin Oxime (Interceptor) 154 reports · 0.5% of its reports
Disorientation after Selamectin (Revolution) 202 reports · 0.7% of its reports
Disorientation after Ivermectin (Heartgard) 246 reports · 2.0% of its reports
Disorientation after Ivermectin + Praziquantel + Pyrantel (Iverhart Max) 45 reports · 0.5% of its reports

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