Allergic reaction after Fluralaner (Bravecto) in dogs

The FDA has received 1,116 reports of allergic reaction in dogs after Fluralaner. That is 1.6% of all reports for this medicine, compared with 2.3% across reports for all dog medicines.

1,116Reports

82%Marked serious

37%Recovered

2.9%Died or euthanised

Same dayTypical onset

How soon it started

Same day

570 65%

1–2 days

152 17%

3–7 days

50 5.7%

1–4 weeks

49 5.6%

Over a month

59 6.7%

How the animals did

Recovered

407 36%

Recovered with lasting effects

5 0.4%

Still unwell when reported

545 49%

Died

20 1.8%

Euthanised

12 1.1%

Not known

127 11%

Problems reported at the same time

394 35%

356 32%

294 26%

165 15%

134 12%

107 9.6%

99 8.9%

87 7.8%

Age of the animals

Under 1 year

109

1–3 years

459

4–7 years

326

8–11 years

145

12+ years

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 allergic reaction in dogs?: 1,116 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 the same 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).

Allergic reaction with similar medicines

Allergic reaction after Afoxolaner (NexGard) 986 reports · 1.7% of its reports
Allergic reaction after Sarolaner (Simparica) 318 reports · 1.9% of its reports
Allergic reaction after Lotilaner (Credelio) 193 reports · 1.9% of its reports
Allergic reaction after Afoxolaner + Moxidectin + Pyrantel (NexGard PLUS) 140 reports · 1.5% of its reports
Allergic reaction after Lotilaner + Moxidectin + Praziquantel + Pyrantel (Credelio Quattro) 56 reports · 1.8% of its reports

All reported side effects of Fluralaner in dogs · Medicines most reported with allergic reaction