Tremors after Afoxolaner + Moxidectin + Pyrantel (NexGard PLUS) in dogs

347 reports to the FDA describe tremors in dogs given Afoxolaner + Moxidectin + Pyrantel. That is 3.7% of all reports for this medicine, compared with 3.4% across reports for all dog medicines.

347Reports

22%Marked serious

49%Recovered

3.7%Died or euthanised

1 daysTypical onset

How soon it started

Same day

153 47%

1–2 days

90 28%

3–7 days

21 6.5%

1–4 weeks

42 13%

Over a month

17 5.3%

How the animals did

Recovered

169 49%

Still unwell when reported

40 12%

Died

6 1.7%

Euthanised

7 2.0%

Not known

125 36%

Problems reported at the same time

94 27%

89 26%

78 22%

60 17%

39 11%

36 10%

32 9.2%

28 8.1%

Age of the animals

Under 1 year

1–3 years

109

4–7 years

8–11 years

12+ years

About this medicine

Afoxolaner kills fleas and ticks; given as a monthly chewable. Moxidectin prevents heartworm disease (monthly topical, or a 6- or 12-month injection for dogs). Pyrantel treats roundworms and hookworms.

Products with this combination include NexGard PLUS. 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 + Moxidectin + Pyrantel cause tremors in dogs?: 347 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).

Tremors with similar medicines

Tremors after Fluralaner (Bravecto) 2,377 reports · 3.5% of its reports
Tremors after Afoxolaner (NexGard) 2,689 reports · 4.7% of its reports
Tremors after Sarolaner (Simparica) 2,370 reports · 14% of its reports
Tremors after Lotilaner (Credelio) 496 reports · 5.0% of its reports
Tremors after Lotilaner + Moxidectin + Praziquantel + Pyrantel (Credelio Quattro) 129 reports · 4.2% of its reports

All reported side effects of Afoxolaner + Moxidectin + Pyrantel in dogs · Medicines most reported with tremors