Behaviour change after Flumethrin + Imidacloprid (Seresto) in dogs

167 reports to the FDA describe behaviour change in dogs given Flumethrin + Imidacloprid. That is 7.3% of all reports for this medicine, compared with 2.5% across reports for all dog medicines, so it is reported unusually often with this medicine.

167Reports

41%Marked serious

35%Recovered

4.2%Died or euthanised

16 daysTypical onset

How soon it started

Same day

17 15%

1–2 days

17 15%

3–7 days

8 7.0%

1–4 weeks

35 30%

Over a month

38 33%

How the animals did

Recovered

58 35%

Recovered with lasting effects

1 0.6%

Still unwell when reported

33 20%

Died

3 1.8%

Euthanised

4 2.4%

Not known

68 41%

Problems reported at the same time

47 28%

44 26%

36 22%

34 20%

31 19%

Restlessness or agitation

25 15%

Vocalising

20 12%

Tremors

20 12%

Age of the animals

Under 1 year

1–3 years

4–7 years

8–11 years

12+ years

About this medicine

Imidacloprid kills fleas (spot-on or collar).

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

Questions owners ask

Can Flumethrin + Imidacloprid cause behaviour change in dogs?: 167 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 16 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).

Behaviour change with similar medicines

Behaviour change after Spinosad (Comfortis) 1,176 reports · 2.1% of its reports
Behaviour change after Lufenuron + Milbemycin Oxime (Sentinel) 358 reports · 1.4% of its reports
Behaviour change after Imidacloprid + Moxidectin (Advantage Multi) 1,205 reports · 9.2% of its reports
Behaviour change after Nitenpyram (Capstar) 323 reports · 3.0% of its reports
Behaviour change after Lufenuron + Milbemycin Oxime + Praziquantel (Sentinel Spectrum) 128 reports · 1.3% of its reports
Behaviour change after Fipronil + S-methoprene (Frontline Plus) 181 reports · 6.1% of its reports
Behaviour change after Imidacloprid 94 reports · 4.9% of its reports
Behaviour change after Fipronil 66 reports · 4.7% of its reports
Behaviour change after Lufenuron 20 reports · 2.0% of its reports
Behaviour change after Imidacloprid + Permethrin + Pyriproxyfen 70 reports · 9.5% of its reports

All reported side effects of Flumethrin + Imidacloprid in dogs · Medicines most reported with behaviour change