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

The FDA has received 3,196 reports of didn't stop ticks in dogs after Pyrantel + Sarolaner. That is 6.0% of all reports for this medicine, compared with 2.3% across reports for all dog medicines, so it is reported unusually often with this medicine.

3,196Reports

37%Marked serious

4.5%Recovered

0.5%Died or euthanised

149 daysTypical onset

How soon it started

Same day

198 11%

1–2 days

20 1.1%

3–7 days

44 2.5%

1–4 weeks

199 11%

Over a month

1,296 74%

How the animals did

Recovered

145 4.5%

Still unwell when reported

2,366 74%

Died

7 0.2%

Euthanised

9 0.3%

Not known

669 21%

Problems reported at the same time

Didn't work as expected

2,257 71%

203 6.4%

122 3.8%

73 2.3%

58 1.8%

31 1.0%

Culture/titer data abnormal

30 0.9%

Didn't stop worms

27 0.8%

Age of the animals

Under 1 year

371

1–3 years

1,350

4–7 years

692

8–11 years

349

12+ years

112

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 ticks in dogs?: 3,196 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 149 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).

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