Vestibular disorder after Afoxolaner (NexGard) in dogs

47 reports to the FDA describe vestibular disorder in dogs given Afoxolaner. That is 0.1% of all reports for this medicine, compared with 0.2% across reports for all dog medicines, so it is reported less often than average with this medicine.

47Reports
55%Marked serious
17%Recovered
13%Died or euthanised
10 daysTypical onset
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How soon it started

Same day
9 22%
1–2 days
5 12%
3–7 days
5 12%
1–4 weeks
9 22%
Over a month
13 32%

How the animals did

Recovered
8 17%
Still unwell when reported
10 21%
Died
2 4.3%
Euthanised
4 8.5%
Not known
23 49%

Problems reported at the same time

Age of the animals

Under 1 year
1
1–3 years
4
4–7 years
10
8–11 years
7
12+ years
24

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 vestibular disorder in dogs?
47 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 10 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).

Vestibular disorder with similar medicines

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