Swelling after Fenbendazole in dogs

129 reports to the FDA describe swelling in dogs given Fenbendazole. That is 2.2% of all reports for this medicine, compared with 2.8% across reports for all dog medicines.

129Reports

40%Marked serious

17%Recovered

16%Died or euthanised

2 daysTypical onset

How soon it started

Same day

20 32%

1–2 days

12 19%

3–7 days

8 13%

1–4 weeks

17 27%

Over a month

5 8.1%

How the animals did

Recovered

22 17%

Still unwell when reported

32 25%

Died

12 9.3%

Euthanised

8 6.2%

Not known

55 43%

Problems reported at the same time

42 33%

30 23%

24 19%

20 16%

20 16%

20 16%

Skin rash or irritation

13 10%

Itching

13 10%

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 swelling in dogs?: 129 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 2 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).

Swelling with similar medicines

Swelling after Pyrantel + Sarolaner (Simparica Trio) 400 reports · 0.7% of its reports
Swelling after Febantel + Praziquantel + Pyrantel (Drontal Plus) 87 reports · 1.3% of its reports
Swelling after Pyrantel 337 reports · 7.0% of its reports
Swelling after Praziquantel + Pyrantel 44 reports · 1.2% of its reports
Swelling after Praziquantel 88 reports · 7.9% of its reports

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