Digestive tract disorder after Afoxolaner (NexGard) in dogs

207 reports to the FDA describe digestive tract disorder in dogs given Afoxolaner. That is 0.4% of all reports for this medicine, compared with 2.0% across reports for all dog medicines, so it is reported less often than average with this medicine.

207Reports
65%Marked serious
27%Recovered
14%Died or euthanised
2 daysTypical onset
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How soon it started

Same day
46 32%
1–2 days
30 21%
3–7 days
10 7.0%
1–4 weeks
22 15%
Over a month
35 24%

How the animals did

Recovered
54 26%
Recovered with lasting effects
2 1.0%
Still unwell when reported
31 15%
Died
21 10%
Euthanised
8 3.9%
Not known
91 44%

Problems reported at the same time

Age of the animals

Under 1 year
49
1–3 years
56
4–7 years
39
8–11 years
28
12+ years
20

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 digestive tract disorder in dogs?
207 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).

Digestive tract disorder with similar medicines

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