Low platelet count after Fenbendazole in dogs

The FDA has received 26 reports of low platelet count in dogs after Fenbendazole. That is 0.4% 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.

26Reports

88%Marked serious

15%Recovered

27%Died or euthanised

14 daysTypical onset

How soon it started

Same day

3 13%

1–2 days

4 17%

3–7 days

2 8.3%

1–4 weeks

11 46%

Over a month

4 17%

How the animals did

Recovered

4 15%

Still unwell when reported

11 42%

Died

3 12%

Euthanised

4 15%

Not known

4 15%

Problems reported at the same time

15 58%

15 58%

14 54%

13 50%

11 42%

11 42%

10 38%

Decreased packed cell volume (pcv)

8 31%

Age of the animals

Under 1 year

1–3 years

4–7 years

8–11 years

12+ years

About this medicine

Fenbendazole treats intestinal worms and some other parasites.

Questions owners ask

Can Fenbendazole cause low platelet count in dogs?: 26 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 14 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).

Low platelet count with similar medicines

Low platelet count after Pyrantel + Sarolaner (Simparica Trio) 59 reports · 0.1% of its reports

All reported side effects of Fenbendazole in dogs · Medicines most reported with low platelet count