Leucocytosis after Metronidazole in dogs

The FDA has received 199 reports of leucocytosis in dogs after Metronidazole. That is 6.4% of all reports for this medicine, compared with 1.0% across reports for all dog medicines, so it is reported unusually often with this medicine.

199Reports

84%Marked serious

8.5%Recovered

43%Died or euthanised

7 daysTypical onset

How soon it started

Same day

27 16%

1–2 days

32 19%

3–7 days

27 16%

1–4 weeks

46 27%

Over a month

39 23%

How the animals did

Recovered

15 7.5%

Recovered with lasting effects

2 1.0%

Still unwell when reported

69 35%

Died

20 10%

Euthanised

66 33%

Not known

27 14%

Problems reported at the same time

124 62%

119 60%

107 54%

106 53%

97 49%

96 48%

86 43%

77 39%

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 leucocytosis in dogs?: 199 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 7 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).

Leucocytosis with similar medicines

Leucocytosis after Amoxicillin + Clavulanate (Clavamox) 349 reports · 6.5% of its reports
Leucocytosis after Doxycycline 210 reports · 5.2% of its reports
Leucocytosis after Cefovecin (Convenia) 175 reports · 4.6% of its reports
Leucocytosis after Enrofloxacin (Baytril) 222 reports · 5.9% of its reports
Leucocytosis after Amoxicillin 102 reports · 7.6% of its reports

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