Diarrhea after Sarolaner (Simparica) in dogs

1,487 reports to the FDA describe diarrhea in dogs given Sarolaner. That is 8.9% of all reports for this medicine, compared with 8.4% across reports for all dog medicines.

1,487Reports
27%Marked serious
30%Recovered
4.9%Died or euthanised
1 daysTypical onset
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How soon it started

Same day
652 47%
1–2 days
412 30%
3–7 days
125 9.0%
1–4 weeks
84 6.0%
Over a month
119 8.5%

How the animals did

Recovered
441 30%
Still unwell when reported
522 35%
Died
28 1.9%
Euthanised
45 3.0%
Not known
451 30%

Problems reported at the same time

Age of the animals

Under 1 year
148
1–3 years
435
4–7 years
353
8–11 years
292
12+ years
177

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 diarrhea in dogs?
1,487 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).

Diarrhea with similar medicines

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