Blood in faeces after Fluralaner (Bravecto) in dogs

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

202Reports
74%Marked serious
25%Recovered
11%Died or euthanised
2 daysTypical onset
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How soon it started

Same day
24 17%
1–2 days
51 37%
3–7 days
24 17%
1–4 weeks
14 10%
Over a month
25 18%

How the animals did

Recovered
48 24%
Recovered with lasting effects
3 1.5%
Still unwell when reported
101 50%
Died
9 4.5%
Euthanised
14 6.9%
Not known
27 13%

Problems reported at the same time

Age of the animals

Under 1 year
14
1–3 years
52
4–7 years
59
8–11 years
48
12+ years
21

About this medicine

Fluralaner kills fleas and ticks for up to 12 weeks (chewable or spot-on).

Products with this ingredient include Bravecto. 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 Fluralaner cause blood in faeces in dogs?
202 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 2 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).

Blood in faeces with similar medicines

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