Itching after Moxidectin (ProHeart 6) in dogs

2,435 reports to the FDA describe itching in dogs given Moxidectin. That is 4.8% of all reports for this medicine, compared with 4.3% across reports for all dog medicines.

2,435Reports

39%Marked serious

29%Recovered

2.3%Died or euthanised

Same dayTypical onset

How soon it started

Same day

1,395 80%

1–2 days

115 6.6%

3–7 days

69 4.0%

1–4 weeks

78 4.5%

Over a month

82 4.7%

How the animals did

Recovered

704 29%

Recovered with lasting effects

4 0.2%

Still unwell when reported

922 38%

Died

35 1.4%

Euthanised

20 0.8%

Not known

750 31%

Problems reported at the same time

1,256 52%

1,026 42%

954 39%

374 15%

266 11%

222 9.1%

190 7.8%

151 6.2%

Age of the animals

Under 1 year

214

1–3 years

1,193

4–7 years

652

8–11 years

260

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 itching in dogs?: 2,435 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).

Itching with similar medicines

Itching after Ivermectin + Pyrantel (Heartgard Plus) 2,733 reports · 1.9% of its reports
Itching after Milbemycin Oxime + Spinosad (Trifexis) 6,069 reports · 4.7% of its reports
Itching after Milbemycin Oxime + Praziquantel (Interceptor Plus) 763 reports · 2.4% of its reports
Itching after Milbemycin Oxime (Interceptor) 563 reports · 1.9% of its reports
Itching after Selamectin (Revolution) 2,024 reports · 6.9% of its reports
Itching after Ivermectin (Heartgard) 528 reports · 4.4% of its reports
Itching after Ivermectin + Praziquantel + Pyrantel (Iverhart Max) 93 reports · 1.1% of its reports
Itching after Moxidectin + Pyrantel + Sarolaner (Simparica Trio) 57 reports · 4.9% of its reports

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