Dehydration after Fluralaner (Bravecto) in cats

121 reports to the FDA describe dehydration in cats given Fluralaner. That is 1.1% of all reports for this medicine, compared with 2.0% across reports for all cat medicines, so it is reported less often than average with this medicine.

121Reports
94%Marked serious
13%Recovered
22%Died or euthanised
1 daysTypical onset
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How soon it started

Same day
43 41%
1–2 days
39 37%
3–7 days
6 5.7%
1–4 weeks
11 10%
Over a month
7 6.6%

How the animals did

Recovered
14 12%
Recovered with lasting effects
2 1.7%
Still unwell when reported
58 48%
Died
11 9.1%
Euthanised
16 13%
Not known
20 17%

Problems reported at the same time

Age of the animals

Under 1 year
5
1–3 years
41
4–7 years
26
8–11 years
24
12+ years
23

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 dehydration in cats?
121 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).

Dehydration with similar medicines

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