Loose stool after Afoxolaner + Moxidectin + Pyrantel (NexGard PLUS) in dogs

The FDA has received 89 reports of loose stool in dogs after Afoxolaner + Moxidectin + Pyrantel. That is 1.0% of all reports for this medicine, compared with 0.9% across reports for all dog medicines.

89Reports

10%Marked serious

47%Recovered

1.1%Died or euthanised

1 daysTypical onset

How soon it started

Same day

41 48%

1–2 days

33 38%

3–7 days

1 1.2%

1–4 weeks

6 7.0%

Over a month

5 5.8%

How the animals did

Recovered

42 47%

Still unwell when reported

8 9.0%

Died

1 1.1%

Not known

38 43%

Problems reported at the same time

35 39%

23 26%

20 22%

7 7.9%

6 6.7%

Inappropriate urination

5 5.6%

Behaviour change

5 5.6%

Diarrhea

5 5.6%

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. 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 loose stool in dogs?: 89 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).

Loose stool with similar medicines

Loose stool after Fluralaner (Bravecto) 614 reports · 0.9% of its reports
Loose stool after Afoxolaner (NexGard) 703 reports · 1.2% of its reports
Loose stool after Sarolaner (Simparica) 178 reports · 1.1% of its reports
Loose stool after Lotilaner (Credelio) 159 reports · 1.6% of its reports
Loose stool after Lotilaner + Moxidectin + Praziquantel + Pyrantel (Credelio Quattro) 62 reports · 2.0% of its reports

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