Skin redness after Flumethrin + Imidacloprid (Seresto) in dogs

The FDA has received 101 reports of skin redness in dogs after Flumethrin + Imidacloprid. That is 4.4% of all reports for this medicine, compared with 1.0% across reports for all dog medicines, so it is reported unusually often with this medicine.

101Reports

54%Marked serious

33%Recovered

5.9%Died or euthanised

24 daysTypical onset

How soon it started

Same day

8 13%

1–2 days

2 3.1%

3–7 days

3 4.7%

1–4 weeks

25 39%

Over a month

26 41%

How the animals did

Recovered

33 33%

Still unwell when reported

13 13%

Died

3 3.0%

Euthanised

3 3.0%

Not known

49 49%

Problems reported at the same time

Itching

55 54%

Application site reaction

39 39%

Hair loss

31 31%

Skin rash or irritation

19 19%

17 17%

11 11%

10 9.9%

8 7.9%

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 skin redness in dogs?: 101 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 24 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).

Skin redness with similar medicines

Skin redness after Spinosad (Comfortis) 266 reports · 0.5% of its reports
Skin redness after Lufenuron + Milbemycin Oxime (Sentinel) 119 reports · 0.5% of its reports
Skin redness after Imidacloprid + Moxidectin (Advantage Multi) 470 reports · 3.6% of its reports
Skin redness after Nitenpyram (Capstar) 102 reports · 0.9% of its reports
Skin redness after Lufenuron + Milbemycin Oxime + Praziquantel (Sentinel Spectrum) 41 reports · 0.4% of its reports
Skin redness after Fipronil + S-methoprene (Frontline Plus) 47 reports · 1.6% of its reports
Skin redness after Imidacloprid 29 reports · 1.5% of its reports
Skin redness after Fipronil 25 reports · 1.8% of its reports
Skin redness after Imidacloprid + Permethrin + Pyriproxyfen 33 reports · 4.5% of its reports

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