Leucopenia after Metronidazole in dogs

The FDA has received 72 reports of leucopenia in dogs after Metronidazole. That is 2.3% of all reports for this medicine, compared with 0.3% across reports for all dog medicines, so it is reported unusually often with this medicine.

72Reports

71%Marked serious

9.7%Recovered

44%Died or euthanised

10 daysTypical onset

How soon it started

Same day

12 18%

1–2 days

12 18%

3–7 days

7 11%

1–4 weeks

7 11%

Over a month

27 42%

How the animals did

Recovered

7 9.7%

Still unwell when reported

26 36%

Died

15 21%

Euthanised

17 24%

Not known

7 9.7%

Problems reported at the same time

41 57%

39 54%

39 54%

37 51%

33 46%

32 44%

32 44%

21 29%

Age of the animals

Under 1 year

1–3 years

4–7 years

8–11 years

12+ years

About this medicine

Metronidazole treats some bacterial and parasitic gut infections.

Questions owners ask

Can Metronidazole cause leucopenia in dogs?: 72 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 10 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).

Leucopenia with similar medicines

Leucopenia after Amoxicillin + Clavulanate (Clavamox) 81 reports · 1.5% of its reports
Leucopenia after Doxycycline 55 reports · 1.4% of its reports
Leucopenia after Cefovecin (Convenia) 63 reports · 1.7% of its reports
Leucopenia after Enrofloxacin (Baytril) 81 reports · 2.1% of its reports

All reported side effects of Metronidazole in dogs · Medicines most reported with leucopenia