Muscle atrophy after Fluralaner (Bravecto) in dogs

41 reports to the FDA describe muscle atrophy in dogs given Fluralaner. That is 0.1% of all reports for this medicine, compared with 0.0% across reports for all dog medicines.

41Reports
95%Marked serious
7.3%Recovered
29%Died or euthanised
22 daysTypical onset
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How soon it started

Same day
4 16%
1–2 days
4 16%
3–7 days
4 16%
1–4 weeks
3 12%
Over a month
10 40%

How the animals did

Recovered
1 2.4%
Recovered with lasting effects
2 4.9%
Still unwell when reported
17 41%
Died
3 7.3%
Euthanised
9 22%
Not known
9 22%

Problems reported at the same time

Age of the animals

Under 1 year
1
1–3 years
5
4–7 years
11
8–11 years
19
12+ years
5

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 muscle atrophy in dogs?
41 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 22 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).

Muscle atrophy with similar medicines

All reported side effects of Fluralaner in dogs · Medicines most reported with muscle atrophy