Weakness after Flumethrin + Imidacloprid (Seresto) in dogs

28 reports to the FDA describe weakness in dogs given Flumethrin + Imidacloprid. That is 1.2% of all reports for this medicine, compared with 1.4% across reports for all dog medicines.

28Reports

64%Marked serious

29%Recovered

11%Died or euthanised

22 daysTypical onset

How soon it started

Same day

3 15%

1–2 days

5 25%

3–7 days

0 0.0%

1–4 weeks

4 20%

Over a month

8 40%

How the animals did

Recovered

8 29%

Still unwell when reported

10 36%

Died

2 7.1%

Euthanised

1 3.6%

Not known

7 25%

Problems reported at the same time

15 54%

12 43%

10 36%

9 32%

8 29%

8 29%

7 25%

6 21%

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 weakness in dogs?: 28 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 22 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).

Weakness with similar medicines

Weakness after Spinosad (Comfortis) 332 reports · 0.6% of its reports
Weakness after Lufenuron + Milbemycin Oxime (Sentinel) 192 reports · 0.7% of its reports
Weakness after Imidacloprid + Moxidectin (Advantage Multi) 159 reports · 1.2% of its reports
Weakness after Nitenpyram (Capstar) 75 reports · 0.7% of its reports
Weakness after Lufenuron + Milbemycin Oxime + Praziquantel (Sentinel Spectrum) 55 reports · 0.6% of its reports
Weakness after Fipronil + S-methoprene (Frontline Plus) 39 reports · 1.3% of its reports
Weakness after Imidacloprid 21 reports · 1.1% of its reports
Weakness after Fipronil 27 reports · 1.9% of its reports

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