Didn't stop fleas after Imidacloprid in dogs

1,054 reports to the FDA describe didn't stop fleas in dogs given Imidacloprid. That is 55% 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.

1,054Reports

3.4%Marked serious

2.2%Recovered

0.4%Died or euthanised

1 daysTypical onset

How soon it started

Same day

215 23%

1–2 days

323 35%

3–7 days

125 13%

1–4 weeks

149 16%

Over a month

114 12%

How the animals did

Recovered

23 2.2%

Still unwell when reported

71 6.7%

Died

2 0.2%

Euthanised

2 0.2%

Not known

956 91%

Problems reported at the same time

160 15%

39 3.7%

27 2.6%

26 2.5%

25 2.4%

Skin rash or irritation

24 2.3%

Product label issues

22 2.1%

Didn't work as expected

21 2.0%

Age of the animals

Under 1 year

1–3 years

161

4–7 years

146

8–11 years

109

12+ years

About this medicine

Imidacloprid kills fleas (spot-on or collar).

Questions owners ask

Can Imidacloprid cause didn't stop fleas in dogs?: 1,054 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 1 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).

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 Imidacloprid + Moxidectin (Advantage Multi) 1,444 reports · 11% 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 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 in dogs · Medicines most reported with didn't stop fleas