Dilated pupils after Nitenpyram (Capstar) in dogs

32 reports to the FDA describe dilated pupils in dogs given Nitenpyram. That is 0.3% of all reports for this medicine, compared with 0.1% across reports for all dog medicines, so it is reported unusually often with this medicine.

32Reports

34%Marked serious

44%Recovered

0.0%Died or euthanised

Same dayTypical onset

How soon it started

Same day

19 68%

1–2 days

3 11%

3–7 days

0 0.0%

1–4 weeks

3 11%

Over a month

3 11%

How the animals did

Recovered

14 44%

Still unwell when reported

10 31%

Not known

8 25%

Problems reported at the same time

Tremors

11 34%

Lethargy

9 28%

Itching

8 25%

Restlessness or agitation

7 22%

7 22%

7 22%

5 16%

4 13%

Age of the animals

Under 1 year

1–3 years

4–7 years

8–11 years

12+ years

About this medicine

Nitenpyram kills adult fleas quickly; a single-dose tablet.

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

Questions owners ask

Can Nitenpyram cause dilated pupils in dogs?: 32 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 the same day 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).

Dilated pupils with similar medicines

Dilated pupils after Spinosad (Comfortis) 97 reports · 0.2% of its reports
Dilated pupils after Imidacloprid + Moxidectin (Advantage Multi) 56 reports · 0.4% of its reports

All reported side effects of Nitenpyram in dogs · Medicines most reported with dilated pupils