Tremors after Fenbendazole in dogs

The FDA has received 229 reports of tremors in dogs after Fenbendazole. That is 3.9% of all reports for this medicine, compared with 3.4% across reports for all dog medicines.

229Reports

44%Marked serious

24%Recovered

9.6%Died or euthanised

1 daysTypical onset

How soon it started

Same day

49 39%

1–2 days

34 27%

3–7 days

14 11%

1–4 weeks

19 15%

Over a month

9 7.2%

How the animals did

Recovered

53 23%

Recovered with lasting effects

2 0.9%

Still unwell when reported

58 25%

Died

6 2.6%

Euthanised

16 7.0%

Not known

94 41%

Problems reported at the same time

80 35%

70 31%

60 26%

53 23%

40 17%

32 14%

29 13%

28 12%

Age of the animals

Under 1 year

111

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 tremors in dogs?: 229 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 1 day 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).

Tremors with similar medicines

Tremors after Pyrantel + Sarolaner (Simparica Trio) 2,595 reports · 4.9% of its reports
Tremors after Febantel + Praziquantel + Pyrantel (Drontal Plus) 149 reports · 2.2% of its reports
Tremors after Pyrantel 198 reports · 4.1% of its reports
Tremors after Praziquantel + Pyrantel 212 reports · 5.8% of its reports
Tremors after Praziquantel 22 reports · 2.0% of its reports

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