Drug administration duration too long after Fenbendazole in dogs

The FDA has received 77 reports of drug administration duration too long in dogs after Fenbendazole. That is 1.3% of all reports for this medicine, compared with 0.1% across reports for all dog medicines, so it is reported unusually often with this medicine.

77Reports

83%Marked serious

30%Recovered

2.6%Died or euthanised

15 daysTypical onset

How soon it started

Same day

5 11%

1–2 days

2 4.5%

3–7 days

4 9.1%

1–4 weeks

25 57%

Over a month

8 18%

How the animals did

Recovered

21 27%

Recovered with lasting effects

2 2.6%

Still unwell when reported

39 51%

Died

1 1.3%

Euthanised

1 1.3%

Not known

13 17%

Problems reported at the same time

Didn't stop worms

25 32%

Didn't work as expected

21 27%

15 19%

13 17%

13 17%

10 13%

9 12%

9 12%

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 drug administration duration too long in dogs?: 77 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 15 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).

All reported side effects of Fenbendazole in dogs · Medicines most reported with drug administration duration too long