Weight gain after Moxidectin (ProHeart 6) in dogs

93 reports to the FDA describe weight gain in dogs given Moxidectin. That is 0.2% of all reports for this medicine, compared with 0.6% across reports for all dog medicines, so it is reported less often than average with this medicine.

93Reports

38%Marked serious

6.5%Recovered

9.7%Died or euthanised

125 daysTypical onset

How soon it started

Same day

5 11%

1–2 days

3 6.8%

3–7 days

1 2.3%

1–4 weeks

5 11%

Over a month

30 68%

How the animals did

Recovered

6 6.5%

Still unwell when reported

41 44%

Died

5 5.4%

Euthanised

4 4.3%

Not known

37 40%

Problems reported at the same time

Didn't prevent heartworm

35 38%

21 23%

15 16%

13 14%

11 12%

10 11%

9 9.7%

9 9.7%

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 weight gain in dogs?: 93 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 125 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).

Weight gain with similar medicines

Weight gain after Ivermectin + Pyrantel (Heartgard Plus) 596 reports · 0.4% of its reports
Weight gain after Milbemycin Oxime + Spinosad (Trifexis) 2,619 reports · 2.0% of its reports
Weight gain after Milbemycin Oxime + Praziquantel (Interceptor Plus) 575 reports · 1.8% of its reports
Weight gain after Milbemycin Oxime (Interceptor) 145 reports · 0.5% of its reports
Weight gain after Selamectin (Revolution) 47 reports · 0.2% of its reports
Weight gain after Ivermectin (Heartgard) 140 reports · 1.2% of its reports
Weight gain after Ivermectin + Praziquantel + Pyrantel (Iverhart Max) 23 reports · 0.3% of its reports
Weight gain after Moxidectin + Pyrantel + Sarolaner (Simparica Trio) 23 reports · 2.0% of its reports

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