Blood problems after Fenbendazole in dogs

123 reports to the FDA describe blood problems in dogs given Fenbendazole. That is 2.1% of all reports for this medicine, compared with 1.8% across reports for all dog medicines.

123Reports

77%Marked serious

13%Recovered

24%Died or euthanised

9 daysTypical onset

How soon it started

Same day

14 15%

1–2 days

10 11%

3–7 days

19 21%

1–4 weeks

35 38%

Over a month

14 15%

How the animals did

Recovered

13 11%

Recovered with lasting effects

3 2.4%

Still unwell when reported

53 43%

Died

12 9.8%

Euthanised

17 14%

Not known

25 20%

Problems reported at the same time

68 55%

60 49%

42 34%

37 30%

29 24%

29 24%

29 24%

25 20%

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 blood problems in dogs?: 123 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 9 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).

Blood problems with similar medicines

Blood problems after Pyrantel + Sarolaner (Simparica Trio) 335 reports · 0.6% of its reports
Blood problems after Febantel + Praziquantel + Pyrantel (Drontal Plus) 51 reports · 0.8% of its reports
Blood problems after Pyrantel 119 reports · 2.5% of its reports
Blood problems after Praziquantel + Pyrantel 24 reports · 0.7% of its reports

All reported side effects of Fenbendazole in dogs · Medicines most reported with blood problems