Seizures after Sarolaner (Simparica) in dogs

The FDA has received 2,972 reports of seizures in dogs after Sarolaner. That is 18% of all reports for this medicine, compared with 4.4% across reports for all dog medicines, so it is reported unusually often with this medicine.

2,972Reports

99%Marked serious

27%Recovered

6.8%Died or euthanised

1 daysTypical onset

How soon it started

Same day

1,242 47%

1–2 days

528 20%

3–7 days

268 10%

1–4 weeks

317 12%

Over a month

309 12%

How the animals did

Recovered

785 26%

Recovered with lasting effects

5 0.2%

Still unwell when reported

1,313 44%

Died

102 3.4%

Euthanised

101 3.4%

Not known

666 22%

Problems reported at the same time

580 20%

281 9.5%

222 7.5%

213 7.2%

195 6.6%

156 5.2%

155 5.2%

148 5.0%

Age of the animals

Under 1 year

159

1–3 years

619

4–7 years

734

8–11 years

737

12+ years

512

About this medicine

Sarolaner kills fleas, ticks and some mites; monthly.

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

In 2018 the FDA alerted owners and vets that isoxazoline products have been associated with neurologic reactions such as muscle tremors, wobbliness (ataxia) and seizures, including in animals with no history of them.

Questions owners ask

Can Sarolaner cause seizures in dogs?: 2,972 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 1 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).

Seizures with similar medicines

Seizures after Fluralaner (Bravecto) 3,501 reports · 5.1% of its reports
Seizures after Afoxolaner (NexGard) 4,287 reports · 7.5% of its reports
Seizures after Lotilaner (Credelio) 686 reports · 6.9% of its reports
Seizures after Afoxolaner + Moxidectin + Pyrantel (NexGard PLUS) 500 reports · 5.4% of its reports
Seizures after Lotilaner + Moxidectin + Praziquantel + Pyrantel (Credelio Quattro) 141 reports · 4.6% of its reports

All reported side effects of Sarolaner in dogs · Medicines most reported with seizures