Loss of appetite after Afoxolaner (NexGard) in dogs

4,773 reports to the FDA describe loss of appetite in dogs given Afoxolaner. That is 8.4% of all reports for this medicine, compared with 8.4% across reports for all dog medicines.

4,773Reports

51%Marked serious

29%Recovered

9.3%Died or euthanised

1 daysTypical onset

How soon it started

Same day

1,283 32%

1–2 days

1,140 28%

3–7 days

384 9.6%

1–4 weeks

418 10%

Over a month

795 20%

How the animals did

Recovered

1,376 29%

Recovered with lasting effects

11 0.2%

Still unwell when reported

480 10%

Died

206 4.3%

Euthanised

238 5.0%

Not known

2,462 52%

Problems reported at the same time

2,560 54%

2,102 44%

1,283 27%

475 10.0%

443 9.3%

436 9.1%

384 8.0%

343 7.2%

Age of the animals

Under 1 year

721

1–3 years

1,111

4–7 years

1,163

8–11 years

1,041

12+ years

523

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 loss of appetite in dogs?: 4,773 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).

Loss of appetite with similar medicines

Loss of appetite after Fluralaner (Bravecto) 4,987 reports · 7.3% of its reports
Loss of appetite after Sarolaner (Simparica) 1,442 reports · 8.7% of its reports
Loss of appetite after Lotilaner (Credelio) 791 reports · 7.9% of its reports
Loss of appetite after Afoxolaner + Moxidectin + Pyrantel (NexGard PLUS) 505 reports · 5.5% of its reports
Loss of appetite after Lotilaner + Moxidectin + Praziquantel + Pyrantel (Credelio Quattro) 302 reports · 9.8% of its reports

All reported side effects of Afoxolaner in dogs · Medicines most reported with loss of appetite