Staring after Afoxolaner (NexGard) in dogs

The FDA has received 193 reports of staring in dogs after Afoxolaner. That is 0.3% of all reports for this medicine, compared with 0.1% across reports for all dog medicines, so it is reported unusually often with this medicine.

193Reports
30%Marked serious
36%Recovered
8.3%Died or euthanised
2 daysTypical onset
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How soon it started

Same day
42 27%
1–2 days
43 28%
3–7 days
29 19%
1–4 weeks
27 17%
Over a month
15 9.6%

How the animals did

Recovered
68 35%
Recovered with lasting effects
1 0.5%
Still unwell when reported
9 4.7%
Died
6 3.1%
Euthanised
10 5.2%
Not known
99 51%

Problems reported at the same time

Age of the animals

Under 1 year
22
1–3 years
49
4–7 years
62
8–11 years
37
12+ years
21

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 staring in dogs?
193 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).

Staring with similar medicines

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