Injection site reaction after Moxidectin (ProHeart 6) in dogs

The FDA has received 1,295 reports of injection site reaction in dogs after Moxidectin. That is 2.6% of all reports for this medicine, compared with 1.0% across reports for all dog medicines, so it is reported unusually often with this medicine.

1,295Reports

35%Marked serious

14%Recovered

3.0%Died or euthanised

6 daysTypical onset

How soon it started

Same day

245 27%

1–2 days

110 12%

3–7 days

148 17%

1–4 weeks

228 26%

Over a month

162 18%

How the animals did

Recovered

179 14%

Still unwell when reported

684 53%

Died

21 1.6%

Euthanised

18 1.4%

Not known

393 30%

Problems reported at the same time

393 30%

175 14%

141 11%

131 10%

105 8.1%

98 7.6%

82 6.3%

71 5.5%

Age of the animals

Under 1 year

1–3 years

412

4–7 years

486

8–11 years

236

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 injection site reaction in dogs?: 1,295 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 6 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).

Injection site reaction with similar medicines

Injection site reaction after Ivermectin + Pyrantel (Heartgard Plus) 301 reports · 0.2% of its reports
Injection site reaction after Milbemycin Oxime + Spinosad (Trifexis) 39 reports · 0.0% of its reports
Injection site reaction after Milbemycin Oxime + Praziquantel (Interceptor Plus) 110 reports · 0.3% of its reports
Injection site reaction after Milbemycin Oxime (Interceptor) 30 reports · 0.1% of its reports
Injection site reaction after Selamectin (Revolution) 29 reports · 0.1% of its reports
Injection site reaction after Ivermectin (Heartgard) 50 reports · 0.4% of its reports

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