Neutrophilia after Fluralaner (Bravecto) in dogs

452 reports to the FDA describe neutrophilia in dogs given Fluralaner. That is 0.7% of all reports for this medicine, compared with 0.6% across reports for all dog medicines.

452Reports

96%Marked serious

6.2%Recovered

32%Died or euthanised

2 daysTypical onset

How soon it started

Same day

84 27%

1–2 days

87 28%

3–7 days

34 11%

1–4 weeks

40 13%

Over a month

64 21%

How the animals did

Recovered

21 4.6%

Recovered with lasting effects

7 1.5%

Still unwell when reported

212 47%

Died

52 12%

Euthanised

93 21%

Not known

67 15%

Problems reported at the same time

255 56%

242 54%

240 53%

229 51%

193 43%

144 32%

143 32%

118 26%

Age of the animals

Under 1 year

1–3 years

106

4–7 years

131

8–11 years

131

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 neutrophilia in dogs?: 452 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).

Neutrophilia with similar medicines

Neutrophilia after Afoxolaner (NexGard) 356 reports · 0.6% of its reports
Neutrophilia after Sarolaner (Simparica) 81 reports · 0.5% of its reports
Neutrophilia after Lotilaner (Credelio) 66 reports · 0.7% of its reports
Neutrophilia after Afoxolaner + Moxidectin + Pyrantel (NexGard PLUS) 54 reports · 0.6% of its reports
Neutrophilia after Lotilaner + Moxidectin + Praziquantel + Pyrantel (Credelio Quattro) 24 reports · 0.8% of its reports

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