Didn't work as expected after Imidacloprid + Moxidectin (Advantage Multi) in dogs

The FDA has received 631 reports of didn't work as expected in dogs after Imidacloprid + Moxidectin. That is 4.8% of all reports for this medicine, compared with 13% across reports for all dog medicines, so it is reported less often than average with this medicine.

631Reports

60%Marked serious

21%Recovered

1.6%Died or euthanised

21 daysTypical onset

How soon it started

Same day

11 3.3%

1–2 days

17 5.0%

3–7 days

35 10%

1–4 weeks

185 55%

Over a month

90 27%

How the animals did

Recovered

134 21%

Recovered with lasting effects

1 0.2%

Still unwell when reported

21 3.3%

Died

5 0.8%

Euthanised

5 0.8%

Not known

465 74%

Problems reported at the same time

Diarrhea

136 22%

Didn't stop worms

84 13%

Vomiting

66 10%

Didn't prevent heartworm

43 6.8%

33 5.2%

28 4.4%

28 4.4%

22 3.5%

Age of the animals

Under 1 year

121

1–3 years

210

4–7 years

146

8–11 years

12+ years

About this medicine

Imidacloprid kills fleas (spot-on or collar). Moxidectin prevents heartworm disease (monthly topical, or a 6- or 12-month injection for dogs).

Products with this combination include Advantage Multi. The FDA hides brand names in its public data, so these reports cover every product with the same active ingredients.

Questions owners ask

Can Imidacloprid + Moxidectin cause didn't work as expected in dogs?: 631 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 21 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).

Didn't work as expected with similar medicines

Didn't work as expected after Spinosad (Comfortis) 1,731 reports · 3.0% of its reports
Didn't work as expected after Lufenuron + Milbemycin Oxime (Sentinel) 4,480 reports · 17% of its reports
Didn't work as expected after Nitenpyram (Capstar) 803 reports · 7.4% of its reports
Didn't work as expected after Lufenuron + Milbemycin Oxime + Praziquantel (Sentinel Spectrum) 1,429 reports · 14% of its reports
Didn't work as expected after Fipronil + S-methoprene (Frontline Plus) 243 reports · 8.2% of its reports
Didn't work as expected after Flumethrin + Imidacloprid (Seresto) 209 reports · 9.2% of its reports
Didn't work as expected after Imidacloprid 105 reports · 5.5% of its reports
Didn't work as expected after Fipronil 152 reports · 11% of its reports
Didn't work as expected after Imidacloprid + Permethrin + Pyriproxyfen 30 reports · 4.1% of its reports
Didn't work as expected after Imidacloprid + Permethrin 70 reports · 15% of its reports

All reported side effects of Imidacloprid + Moxidectin in dogs · Medicines most reported with didn't work as expected