Dilated pupils after Pyrantel + Sarolaner (Simparica Trio) in dogs

The FDA has received 78 reports of dilated pupils in dogs after Pyrantel + Sarolaner. That is 0.1% of all reports for this medicine, compared with 0.1% across reports for all dog medicines.

78Reports

67%Marked serious

26%Recovered

6.4%Died or euthanised

Same dayTypical onset

How soon it started

Same day

40 53%

1–2 days

21 28%

3–7 days

9 12%

1–4 weeks

2 2.7%

Over a month

3 4.0%

How the animals did

Recovered

20 26%

Still unwell when reported

41 53%

Died

3 3.8%

Euthanised

2 2.6%

Not known

12 15%

Problems reported at the same time

31 40%

26 33%

21 27%

19 24%

16 21%

12 15%

12 15%

11 14%

Age of the animals

Under 1 year

1–3 years

4–7 years

8–11 years

12+ years

About this medicine

Pyrantel treats roundworms and hookworms. Sarolaner kills fleas, ticks and some mites; monthly.

Products with this combination include Simparica Trio (which also contains moxidectin). The FDA hides brand names in its public data, so these reports cover every product with the same active ingredients.

Questions owners ask

Can Pyrantel + Sarolaner cause dilated pupils in dogs?: 78 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).

All reported side effects of Pyrantel + Sarolaner in dogs · Medicines most reported with dilated pupils