Allergic reaction after Moxidectin (ProHeart 6) in dogs

The FDA has received 9,936 reports of allergic reaction in dogs after Moxidectin. That is 20% of all reports for this medicine, compared with 2.3% across reports for all dog medicines, so it is reported unusually often with this medicine.

9,936Reports

50%Marked serious

37%Recovered

2.5%Died or euthanised

Same dayTypical onset

How soon it started

Same day

7,046 93%

1–2 days

250 3.3%

3–7 days

80 1.1%

1–4 weeks

83 1.1%

Over a month

82 1.1%

How the animals did

Recovered

3,634 37%

Recovered with lasting effects

1 0.0%

Still unwell when reported

3,551 36%

Died

204 2.1%

Euthanised

44 0.4%

Not known

2,502 25%

Problems reported at the same time

5,055 51%

4,954 50%

1,767 18%

1,507 15%

1,270 13%

1,266 13%

1,256 13%

1,181 12%

Age of the animals

Under 1 year

1,104

1–3 years

5,731

4–7 years

2,165

8–11 years

637

12+ years

141

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 allergic reaction in dogs?: 9,936 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).

Allergic reaction with similar medicines

Allergic reaction after Ivermectin + Pyrantel (Heartgard Plus) 788 reports · 0.5% of its reports
Allergic reaction after Milbemycin Oxime + Spinosad (Trifexis) 1,103 reports · 0.9% of its reports
Allergic reaction after Milbemycin Oxime + Praziquantel (Interceptor Plus) 402 reports · 1.3% of its reports
Allergic reaction after Milbemycin Oxime (Interceptor) 274 reports · 0.9% of its reports
Allergic reaction after Selamectin (Revolution) 473 reports · 1.6% of its reports
Allergic reaction after Ivermectin (Heartgard) 160 reports · 1.3% of its reports
Allergic reaction after Ivermectin + Praziquantel + Pyrantel (Iverhart Max) 70 reports · 0.8% of its reports

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