Disorientation after Afoxolaner (NexGard) in dogs

663 reports to the FDA describe disorientation in dogs given Afoxolaner. That is 1.2% of all reports for this medicine, compared with 1.0% across reports for all dog medicines.

663Reports

52%Marked serious

40%Recovered

8.7%Died or euthanised

3 daysTypical onset

How soon it started

Same day

159 28%

1–2 days

120 21%

3–7 days

74 13%

1–4 weeks

88 16%

Over a month

121 22%

How the animals did

Recovered

263 40%

Still unwell when reported

45 6.8%

Died

26 3.9%

Euthanised

32 4.8%

Not known

297 45%

Problems reported at the same time

323 49%

174 26%

145 22%

108 16%

102 15%

100 15%

83 13%

82 12%

Age of the animals

Under 1 year

1–3 years

164

4–7 years

162

8–11 years

144

12+ years

101

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 disorientation 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).

Disorientation with similar medicines

Disorientation after Fluralaner (Bravecto) 660 reports · 1.0% of its reports
Disorientation after Sarolaner (Simparica) 349 reports · 2.1% of its reports
Disorientation after Lotilaner (Credelio) 109 reports · 1.1% of its reports
Disorientation after Afoxolaner + Moxidectin + Pyrantel (NexGard PLUS) 109 reports · 1.2% of its reports
Disorientation after Lotilaner + Moxidectin + Praziquantel + Pyrantel (Credelio Quattro) 28 reports · 0.9% of its reports

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