Pale mucous membrane after Afoxolaner (NexGard) in dogs

The FDA has received 225 reports of pale mucous membrane in dogs after Afoxolaner. That is 0.4% of all reports for this medicine, compared with 0.7% across reports for all dog medicines, so it is reported less often than average with this medicine.

225Reports

81%Marked serious

25%Recovered

27%Died or euthanised

1 daysTypical onset

How soon it started

Same day

58 31%

1–2 days

53 28%

3–7 days

15 8.0%

1–4 weeks

28 15%

Over a month

34 18%

How the animals did

Recovered

55 24%

Recovered with lasting effects

1 0.4%

Still unwell when reported

26 12%

Died

29 13%

Euthanised

32 14%

Not known

82 36%

Problems reported at the same time

130 58%

92 41%

84 37%

76 34%

63 28%

60 27%

46 20%

44 20%

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 pale mucous membrane in dogs?: 225 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).

Pale mucous membrane with similar medicines

Pale mucous membrane after Fluralaner (Bravecto) 267 reports · 0.4% of its reports
Pale mucous membrane after Sarolaner (Simparica) 66 reports · 0.4% of its reports
Pale mucous membrane after Lotilaner (Credelio) 65 reports · 0.7% of its reports
Pale mucous membrane after Afoxolaner + Moxidectin + Pyrantel (NexGard PLUS) 20 reports · 0.2% of its reports
Pale mucous membrane after Lotilaner + Moxidectin + Praziquantel + Pyrantel (Credelio Quattro) 22 reports · 0.7% of its reports

All reported side effects of Afoxolaner in dogs · Medicines most reported with pale mucous membrane