Stumbling gait after Afoxolaner (NexGard) in dogs

The FDA has received 166 reports of stumbling gait in dogs after Afoxolaner. That is 0.3% of all reports for this medicine, compared with 0.2% across reports for all dog medicines.

166Reports
39%Marked serious
42%Recovered
9.6%Died or euthanised
1 daysTypical onset
SponsoredWorried about your pet? Ask a veterinarian online, 24/7

How soon it started

Same day
47 36%
1–2 days
27 21%
3–7 days
9 6.9%
1–4 weeks
19 15%
Over a month
29 22%

How the animals did

Recovered
68 41%
Recovered with lasting effects
1 0.6%
Still unwell when reported
14 8.4%
Died
9 5.4%
Euthanised
7 4.2%
Not known
67 40%

Problems reported at the same time

Age of the animals

Under 1 year
27
1–3 years
32
4–7 years
27
8–11 years
43
12+ years
32

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 stumbling gait in dogs?
166 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 1 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).

Stumbling gait with similar medicines

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