Underdose after Moxidectin (ProHeart 6) in dogs

180 reports to the FDA describe underdose in dogs given Moxidectin. That is 0.4% 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.

180Reports

81%Marked serious

11%Recovered

3.9%Died or euthanised

54 daysTypical onset

How soon it started

Same day

29 23%

1–2 days

9 7.2%

3–7 days

6 4.8%

1–4 weeks

12 9.6%

Over a month

69 55%

How the animals did

Recovered

19 11%

Recovered with lasting effects

1 0.6%

Still unwell when reported

134 74%

Died

6 3.3%

Euthanised

1 0.6%

Not known

19 11%

Problems reported at the same time

Didn't stop worms

61 34%

Didn't prevent heartworm

55 31%

22 12%

20 11%

15 8.3%

12 6.7%

12 6.7%

11 6.1%

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 underdose in dogs?: 180 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 54 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).

Underdose with similar medicines

Underdose after Ivermectin + Pyrantel (Heartgard Plus) 1,810 reports · 1.2% of its reports
Underdose after Milbemycin Oxime + Spinosad (Trifexis) 750 reports · 0.6% of its reports
Underdose after Milbemycin Oxime + Praziquantel (Interceptor Plus) 153 reports · 0.5% of its reports
Underdose after Milbemycin Oxime (Interceptor) 118 reports · 0.4% of its reports
Underdose after Selamectin (Revolution) 179 reports · 0.6% of its reports
Underdose after Ivermectin (Heartgard) 99 reports · 0.8% of its reports
Underdose after Ivermectin + Praziquantel + Pyrantel (Iverhart Max) 98 reports · 1.1% of its reports

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