Lameness after Fenbendazole in dogs

The FDA has received 44 reports of lameness in dogs after Fenbendazole. That is 0.7% of all reports for this medicine, compared with 0.6% across reports for all dog medicines.

44Reports

50%Marked serious

20%Recovered

14%Died or euthanised

16 daysTypical onset

How soon it started

Same day

3 12%

1–2 days

1 3.8%

3–7 days

3 12%

1–4 weeks

10 38%

Over a month

9 35%

How the animals did

Recovered

9 20%

Still unwell when reported

14 32%

Died

4 9.1%

Euthanised

2 4.5%

Not known

15 34%

Problems reported at the same time

16 36%

11 25%

10 23%

9 20%

8 18%

8 18%

7 16%

7 16%

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 lameness in dogs?: 44 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 16 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).

Lameness with similar medicines

Lameness after Pyrantel + Sarolaner (Simparica Trio) 147 reports · 0.3% of its reports
Lameness after Febantel + Praziquantel + Pyrantel (Drontal Plus) 20 reports · 0.3% of its reports
Lameness after Pyrantel 47 reports · 1.0% of its reports

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