Lethargy after Praziquantel in dogs

The FDA has received 148 reports of lethargy in dogs after Praziquantel. That is 13% of all reports for this medicine, compared with 11% across reports for all dog medicines.

148Reports

30%Marked serious

21%Recovered

9.5%Died or euthanised

1 daysTypical onset

How soon it started

Same day

40 38%

1–2 days

32 31%

3–7 days

13 13%

1–4 weeks

11 11%

Over a month

8 7.7%

How the animals did

Recovered

28 19%

Recovered with lasting effects

3 2.0%

Still unwell when reported

24 16%

Died

12 8.1%

Euthanised

2 1.4%

Not known

79 53%

Problems reported at the same time

59 40%

50 34%

30 20%

14 9.5%

12 8.1%

11 7.4%

Drooling

10 6.8%

Wobbliness (ataxia)

10 6.8%

Age of the animals

Under 1 year

1–3 years

4–7 years

8–11 years

12+ years

About this medicine

Praziquantel treats tapeworms.

Questions owners ask

Can Praziquantel cause lethargy in dogs?: 148 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).

Lethargy with similar medicines

Lethargy after Pyrantel + Sarolaner (Simparica Trio) 3,702 reports · 6.9% of its reports
Lethargy after Febantel + Praziquantel + Pyrantel (Drontal Plus) 651 reports · 9.7% of its reports
Lethargy after Fenbendazole 1,078 reports · 18% of its reports
Lethargy after Pyrantel 928 reports · 19% of its reports
Lethargy after Praziquantel + Pyrantel 956 reports · 26% of its reports

All reported side effects of Praziquantel in dogs · Medicines most reported with lethargy