Didn't stop fleas after Pyrantel + Sarolaner (Simparica Trio) in dogs

The FDA has received 1,757 reports of didn't stop fleas in dogs after Pyrantel + Sarolaner. That is 3.3% of all reports for this medicine, compared with 6.2% across reports for all dog medicines, so it is reported less often than average with this medicine.

1,757Reports

22%Marked serious

2.1%Recovered

0.1%Died or euthanised

38 daysTypical onset

How soon it started

Same day

292 22%

1–2 days

22 1.6%

3–7 days

62 4.6%

1–4 weeks

252 19%

Over a month

712 53%

How the animals did

Recovered

37 2.1%

Still unwell when reported

796 45%

Died

1 0.1%

Euthanised

1 0.1%

Not known

922 52%

Problems reported at the same time

58 3.3%

43 2.4%

26 1.5%

24 1.4%

21 1.2%

19 1.1%

13 0.7%

Didn't work as expected

11 0.6%

Age of the animals

Under 1 year

232

1–3 years

518

4–7 years

339

8–11 years

219

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 didn't stop fleas in dogs?: 1,757 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 38 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).

Didn't stop fleas with similar medicines

Didn't stop fleas after Fenbendazole 24 reports · 0.4% of its reports
Didn't stop fleas after Pyrantel 25 reports · 0.5% of its reports
Didn't stop fleas after Praziquantel + Pyrantel 28 reports · 0.8% of its reports

All reported side effects of Pyrantel + Sarolaner in dogs · Medicines most reported with didn't stop fleas