Itching after Imidacloprid + Permethrin in dogs

49 reports to the FDA describe itching in dogs given Imidacloprid + Permethrin. That is 10% of all reports for this medicine, compared with 4.3% across reports for all dog medicines, so it is reported unusually often with this medicine.

49Reports

24%Marked serious

31%Recovered

10%Died or euthanised

21 daysTypical onset

How soon it started

Same day

8 25%

1–2 days

2 6.3%

3–7 days

1 3.1%

1–4 weeks

9 28%

Over a month

12 38%

How the animals did

Recovered

10 20%

Recovered with lasting effects

5 10%

Still unwell when reported

12 24%

Died

4 8.2%

Euthanised

1 2.0%

Not known

17 35%

Problems reported at the same time

15 31%

12 24%

8 16%

8 16%

Didn't work as expected

6 12%

Skin rash or irritation

6 12%

Skin redness

5 10%

Death

5 10%

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).

Questions owners ask

Can Imidacloprid + Permethrin cause itching in dogs?: 49 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).

Itching with similar medicines

Itching after Spinosad (Comfortis) 3,874 reports · 6.8% of its reports
Itching after Lufenuron + Milbemycin Oxime (Sentinel) 1,223 reports · 4.7% of its reports
Itching after Imidacloprid + Moxidectin (Advantage Multi) 2,227 reports · 17% of its reports
Itching after Nitenpyram (Capstar) 1,450 reports · 13% of its reports
Itching after Lufenuron + Milbemycin Oxime + Praziquantel (Sentinel Spectrum) 281 reports · 2.8% of its reports
Itching after Fipronil + S-methoprene (Frontline Plus) 330 reports · 11% of its reports
Itching after Flumethrin + Imidacloprid (Seresto) 610 reports · 27% of its reports
Itching after Imidacloprid 297 reports · 16% of its reports
Itching after Fipronil 138 reports · 9.8% of its reports
Itching after Lufenuron 178 reports · 17% of its reports

All reported side effects of Imidacloprid + Permethrin in dogs · Medicines most reported with itching