Overdose after Moxidectin (ProHeart 6) in dogs

The FDA has received 366 reports of overdose in dogs after Moxidectin. That is 0.7% of all reports for this medicine, compared with 1.3% across reports for all dog medicines, so it is reported less often than average with this medicine.

366Reports

77%Marked serious

8.5%Recovered

2.7%Died or euthanised

31 daysTypical onset

How soon it started

Same day

68 31%

1–2 days

19 8.6%

3–7 days

12 5.5%

1–4 weeks

11 5.0%

Over a month

110 50%

How the animals did

Recovered

31 8.5%

Still unwell when reported

294 80%

Died

6 1.6%

Euthanised

4 1.1%

Not known

31 8.5%

Problems reported at the same time

Didn't prevent heartworm

145 40%

Didn't stop worms

81 22%

Vomiting

60 16%

Drug dose administration interval too long

42 11%

Lethargy

38 10%

Diarrhea

37 10%

Medication error

37 10%

Drug dose administration interval too short

27 7.4%

Age of the animals

Under 1 year

1–3 years

149

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 overdose in dogs?: 366 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 31 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).

Overdose with similar medicines

Overdose after Ivermectin + Pyrantel (Heartgard Plus) 1,647 reports · 1.1% of its reports
Overdose after Milbemycin Oxime + Spinosad (Trifexis) 2,052 reports · 1.6% of its reports
Overdose after Milbemycin Oxime + Praziquantel (Interceptor Plus) 266 reports · 0.8% of its reports
Overdose after Milbemycin Oxime (Interceptor) 131 reports · 0.4% of its reports
Overdose after Selamectin (Revolution) 160 reports · 0.5% of its reports
Overdose after Ivermectin (Heartgard) 134 reports · 1.1% of its reports
Overdose after Ivermectin + Praziquantel + Pyrantel (Iverhart Max) 185 reports · 2.2% of its reports
Overdose after Moxidectin + Pyrantel + Sarolaner (Simparica Trio) 31 reports · 2.7% of its reports

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