Application site reaction after Flumethrin + Imidacloprid (Seresto) in dogs

The FDA has received 123 reports of application site reaction in dogs after Flumethrin + Imidacloprid. That is 5.4% of all reports for this medicine, compared with 0.4% across reports for all dog medicines, so it is reported unusually often with this medicine.

123Reports

43%Marked serious

28%Recovered

3.3%Died or euthanised

21 daysTypical onset

How soon it started

Same day

14 15%

1–2 days

6 6.5%

3–7 days

5 5.4%

1–4 weeks

30 33%

Over a month

37 40%

How the animals did

Recovered

35 28%

Still unwell when reported

31 25%

Died

3 2.4%

Euthanised

1 0.8%

Not known

53 43%

Problems reported at the same time

Itching

48 39%

Hair loss

44 36%

Skin redness

39 32%

Skin rash or irritation

21 17%

18 15%

11 8.9%

10 8.1%

8 6.5%

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 application site reaction in dogs?: 123 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).

Application site reaction with similar medicines

Application site reaction after Imidacloprid + Moxidectin (Advantage Multi) 658 reports · 5.0% of its reports
Application site reaction after Fipronil + S-methoprene (Frontline Plus) 185 reports · 6.3% of its reports
Application site reaction after Imidacloprid + Permethrin + Pyriproxyfen 40 reports · 5.4% of its reports
Application site reaction after Cyphenothrin + Fipronil + S-methoprene 83 reports · 13% of its reports
Application site reaction after Amitraz + Fipronil + S-methoprene 73 reports · 16% of its reports
Application site reaction after Fipronil + Pyriproxyfen + S-methoprene 24 reports · 5.6% of its reports

All reported side effects of Flumethrin + Imidacloprid in dogs · Medicines most reported with application site reaction