Blood in faeces after Sarolaner (Simparica) in dogs

42 reports to the FDA describe blood in faeces in dogs given Sarolaner. That is 0.3% of all reports for this medicine, compared with 0.2% across reports for all dog medicines.

42Reports
43%Marked serious
4.8%Recovered
9.5%Died or euthanised
1 daysTypical onset
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How soon it started

Same day
14 36%
1–2 days
10 26%
3–7 days
2 5.1%
1–4 weeks
4 10%
Over a month
9 23%

How the animals did

Recovered
2 4.8%
Still unwell when reported
21 50%
Died
2 4.8%
Euthanised
2 4.8%
Not known
15 36%

Problems reported at the same time

Age of the animals

Under 1 year
2
1–3 years
13
4–7 years
10
8–11 years
10
12+ years
6

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 blood in faeces in dogs?
42 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).

Blood in faeces with similar medicines

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