Hair shedding after Afoxolaner (NexGard) in dogs

93 reports to the FDA describe hair shedding in dogs given Afoxolaner. That is 0.2% 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.

93Reports
61%Marked serious
14%Recovered
1.1%Died or euthanised
3 daysTypical onset
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How soon it started

Same day
28 36%
1–2 days
8 10%
3–7 days
15 19%
1–4 weeks
6 7.7%
Over a month
21 27%

How the animals did

Recovered
13 14%
Still unwell when reported
5 5.4%
Euthanised
1 1.1%
Not known
74 80%

Problems reported at the same time

Age of the animals

Under 1 year
8
1–3 years
23
4–7 years
27
8–11 years
14
12+ years
9

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 hair shedding in dogs?
93 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).

Hair shedding with similar medicines

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