Bacterial skin infection after Afoxolaner (NexGard) in dogs

The FDA has received 70 reports of bacterial skin infection in dogs after Afoxolaner. That is 0.1% of all reports for this medicine, compared with 0.1% across reports for all dog medicines.

70Reports

47%Marked serious

19%Recovered

4.3%Died or euthanised

7 daysTypical onset

How soon it started

Same day

10 19%

1–2 days

11 21%

3–7 days

6 11%

1–4 weeks

9 17%

Over a month

17 32%

How the animals did

Recovered

12 17%

Recovered with lasting effects

1 1.4%

Still unwell when reported

14 20%

Died

2 2.9%

Euthanised

1 1.4%

Not known

40 57%

Problems reported at the same time

Itching

31 44%

Skin rash or irritation

21 30%

19 27%

16 23%

13 19%

11 16%

10 14%

Fungal skin infection

9 13%

Age of the animals

Under 1 year

1–3 years

4–7 years

8–11 years

12+ years

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 bacterial skin infection in dogs?: 70 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 7 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).

Bacterial skin infection with similar medicines

Bacterial skin infection after Fluralaner (Bravecto) 86 reports · 0.1% of its reports
Bacterial skin infection after Sarolaner (Simparica) 25 reports · 0.2% of its reports

All reported side effects of Afoxolaner in dogs · Medicines most reported with bacterial skin infection