Restlessness or agitation after Afoxolaner (NexGard) in dogs

The FDA has received 1,179 reports of restlessness or agitation in dogs after Afoxolaner. That is 2.1% of all reports for this medicine, compared with 1.6% across reports for all dog medicines.

1,179Reports

44%Marked serious

37%Recovered

3.6%Died or euthanised

Same dayTypical onset

How soon it started

Same day

623 62%

1–2 days

156 15%

3–7 days

31 3.1%

1–4 weeks

58 5.7%

Over a month

145 14%

How the animals did

Recovered

439 37%

Recovered with lasting effects

1 0.1%

Still unwell when reported

90 7.6%

Died

24 2.0%

Euthanised

19 1.6%

Not known

606 51%

Problems reported at the same time

504 43%

363 31%

201 17%

183 16%

155 13%

133 11%

118 10%

114 9.7%

Age of the animals

Under 1 year

169

1–3 years

279

4–7 years

321

8–11 years

240

12+ years

113

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 restlessness or agitation in dogs?: 1,179 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).

Restlessness or agitation with similar medicines

Restlessness or agitation after Fluralaner (Bravecto) 624 reports · 0.9% of its reports
Restlessness or agitation after Sarolaner (Simparica) 291 reports · 1.7% of its reports
Restlessness or agitation after Lotilaner (Credelio) 139 reports · 1.4% of its reports
Restlessness or agitation after Afoxolaner + Moxidectin + Pyrantel (NexGard PLUS) 93 reports · 1.0% of its reports
Restlessness or agitation after Lotilaner + Moxidectin + Praziquantel + Pyrantel (Credelio Quattro) 33 reports · 1.1% of its reports

All reported side effects of Afoxolaner in dogs · Medicines most reported with restlessness or agitation