Didn't stop fleas after Imidacloprid + Moxidectin (Advantage Multi) in dogs

1,444 reports to the FDA describe didn't stop fleas in dogs given Imidacloprid + Moxidectin. That is 11% of all reports for this medicine, compared with 6.2% across reports for all dog medicines, so it is reported unusually often with this medicine.

1,444Reports

24%Marked serious

9.1%Recovered

0.5%Died or euthanised

15 daysTypical onset

How soon it started

Same day

52 6.0%

1–2 days

92 11%

3–7 days

125 15%

1–4 weeks

428 50%

Over a month

163 19%

How the animals did

Recovered

131 9.1%

Still unwell when reported

67 4.6%

Died

4 0.3%

Euthanised

3 0.2%

Not known

1,239 86%

Problems reported at the same time

Itching

628 43%

Skin rash or irritation

81 5.6%

Drug dose administration interval too short

56 3.9%

Drug dose administration interval too long

48 3.3%

40 2.8%

37 2.6%

30 2.1%

26 1.8%

Age of the animals

Under 1 year

109

1–3 years

312

4–7 years

343

8–11 years

270

12+ years

129

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 stop fleas in dogs?: 1,444 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 15 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 stop fleas with similar medicines

Didn't stop fleas after Spinosad (Comfortis) 13,280 reports · 23% of its reports
Didn't stop fleas after Lufenuron + Milbemycin Oxime (Sentinel) 977 reports · 3.8% of its reports
Didn't stop fleas after Nitenpyram (Capstar) 6,142 reports · 57% of its reports
Didn't stop fleas after Lufenuron + Milbemycin Oxime + Praziquantel (Sentinel Spectrum) 498 reports · 5.0% of its reports
Didn't stop fleas after Fipronil + S-methoprene (Frontline Plus) 576 reports · 19% of its reports
Didn't stop fleas after Flumethrin + Imidacloprid (Seresto) 882 reports · 39% of its reports
Didn't stop fleas after Imidacloprid 1,054 reports · 55% of its reports
Didn't stop fleas after Fipronil 394 reports · 28% of its reports
Didn't stop fleas after Lufenuron 44 reports · 4.3% of its reports
Didn't stop fleas after Imidacloprid + Permethrin + Pyriproxyfen 219 reports · 30% of its reports

All reported side effects of Imidacloprid + Moxidectin in dogs · Medicines most reported with didn't stop fleas