Neutrophilia after Fenbendazole in dogs

51 reports to the FDA describe neutrophilia in dogs given Fenbendazole. That is 0.9% of all reports for this medicine, compared with 0.6% across reports for all dog medicines.

51Reports

82%Marked serious

22%Recovered

22%Died or euthanised

13 daysTypical onset

How soon it started

Same day

9 23%

1–2 days

3 7.5%

3–7 days

4 10%

1–4 weeks

15 38%

Over a month

9 23%

How the animals did

Recovered

11 22%

Still unwell when reported

19 37%

Died

1 2.0%

Euthanised

10 20%

Not known

10 20%

Problems reported at the same time

31 61%

24 47%

21 41%

20 39%

17 33%

14 27%

Decreased haemoglobin

13 25%

Didn't work as expected

13 25%

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 neutrophilia in dogs?: 51 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 13 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).

Neutrophilia with similar medicines

Neutrophilia after Pyrantel + Sarolaner (Simparica Trio) 146 reports · 0.3% of its reports
Neutrophilia after Febantel + Praziquantel + Pyrantel (Drontal Plus) 22 reports · 0.3% of its reports
Neutrophilia after Pyrantel 41 reports · 0.9% of its reports

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