Blood problems after Fluralaner (Bravecto) in cats

The FDA has received 68 reports of blood problems in cats after Fluralaner. That is 0.6% of all reports for this medicine, compared with 1.9% across reports for all cat medicines, so it is reported less often than average with this medicine.

68Reports
93%Marked serious
10%Recovered
35%Died or euthanised
3 daysTypical onset
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How soon it started

Same day
13 24%
1–2 days
14 26%
3–7 days
5 9.3%
1–4 weeks
11 20%
Over a month
11 20%

How the animals did

Recovered
6 8.8%
Recovered with lasting effects
1 1.5%
Still unwell when reported
23 34%
Died
8 12%
Euthanised
16 24%
Not known
14 21%

Problems reported at the same time

Age of the animals

Under 1 year
2
1–3 years
17
4–7 years
10
8–11 years
17
12+ years
18

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 problems in cats?
68 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 3 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 problems with similar medicines

All reported side effects of Fluralaner in cats · Medicines most reported with blood problems