Leucocytosis after Pyrantel in dogs

The FDA has received 60 reports of leucocytosis in dogs after Pyrantel. That is 1.3% of all reports for this medicine, compared with 1.0% across reports for all dog medicines.

60Reports

58%Marked serious

10%Recovered

37%Died or euthanised

5 daysTypical onset

How soon it started

Same day

14 29%

1–2 days

8 17%

3–7 days

8 17%

1–4 weeks

12 25%

Over a month

6 13%

How the animals did

Recovered

6 10%

Still unwell when reported

21 35%

Died

10 17%

Euthanised

12 20%

Not known

11 18%

Problems reported at the same time

39 65%

31 52%

29 48%

26 43%

22 37%

22 37%

21 35%

21 35%

Age of the animals

Under 1 year

1–3 years

4–7 years

8–11 years

12+ years

About this medicine

Pyrantel treats roundworms and hookworms.

Questions owners ask

Can Pyrantel cause leucocytosis in dogs?: 60 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 5 days 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).

Leucocytosis with similar medicines

Leucocytosis after Pyrantel + Sarolaner (Simparica Trio) 173 reports · 0.3% of its reports
Leucocytosis after Febantel + Praziquantel + Pyrantel (Drontal Plus) 29 reports · 0.4% of its reports
Leucocytosis after Fenbendazole 69 reports · 1.2% of its reports

All reported side effects of Pyrantel in dogs · Medicines most reported with leucocytosis