Constipation after Praziquantel + Pyrantel in dogs

The FDA has received 41 reports of constipation in dogs after Praziquantel + Pyrantel. That is 1.1% of all reports for this medicine, compared with 0.2% across reports for all dog medicines, so it is reported unusually often with this medicine.

41Reports

34%Marked serious

27%Recovered

4.9%Died or euthanised

1 daysTypical onset

How soon it started

Same day

17 50%

1–2 days

12 35%

3–7 days

2 5.9%

1–4 weeks

3 8.8%

Over a month

0 0.0%

How the animals did

Recovered

11 27%

Still unwell when reported

1 2.4%

Died

1 2.4%

Euthanised

1 2.4%

Not known

27 66%

Problems reported at the same time

14 34%

9 22%

9 22%

7 17%

6 15%

5 12%

Distension of abdomen

3 7.3%

Flatulence

2 4.9%

Age of the animals

Under 1 year

1–3 years

4–7 years

8–11 years

12+ years

About this medicine

Praziquantel treats tapeworms. Pyrantel treats roundworms and hookworms.

Questions owners ask

Can Praziquantel + Pyrantel cause constipation in dogs?: 41 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).

Constipation with similar medicines

Constipation after Pyrantel + Sarolaner (Simparica Trio) 42 reports · 0.1% of its reports
Constipation after Febantel + Praziquantel + Pyrantel (Drontal Plus) 28 reports · 0.4% of its reports
Constipation after Fenbendazole 44 reports · 0.7% of its reports
Constipation after Pyrantel 24 reports · 0.5% of its reports

All reported side effects of Praziquantel + Pyrantel in dogs · Medicines most reported with constipation