Kidney problems after Afoxolaner (NexGard) in dogs

The FDA has received 663 reports of kidney problems in dogs after Afoxolaner. That is 1.2% of all reports for this medicine, compared with 2.4% across reports for all dog medicines, so it is reported less often than average with this medicine.

663Reports

71%Marked serious

9.5%Recovered

30%Died or euthanised

3 daysTypical onset

How soon it started

Same day

108 22%

1–2 days

127 26%

3–7 days

60 12%

1–4 weeks

69 14%

Over a month

123 25%

How the animals did

Recovered

60 9.0%

Recovered with lasting effects

3 0.5%

Still unwell when reported

133 20%

Died

90 14%

Euthanised

111 17%

Not known

266 40%

Problems reported at the same time

276 42%

275 41%

267 40%

246 37%

198 30%

138 21%

123 19%

104 16%

Age of the animals

Under 1 year

1–3 years

100

4–7 years

137

8–11 years

176

12+ years

169

About this medicine

Afoxolaner kills fleas and ticks; given as a monthly chewable.

Products with this ingredient include NexGard. 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 Afoxolaner cause kidney problems in dogs?: 663 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).

Kidney problems with similar medicines

Kidney problems after Fluralaner (Bravecto) 896 reports · 1.3% of its reports
Kidney problems after Sarolaner (Simparica) 209 reports · 1.3% of its reports
Kidney problems after Lotilaner (Credelio) 144 reports · 1.4% of its reports
Kidney problems after Afoxolaner + Moxidectin + Pyrantel (NexGard PLUS) 84 reports · 0.9% of its reports
Kidney problems after Lotilaner + Moxidectin + Praziquantel + Pyrantel (Credelio Quattro) 34 reports · 1.1% of its reports

All reported side effects of Afoxolaner in dogs · Medicines most reported with kidney problems