Elevated haematocrit after Metronidazole in dogs

26 reports to the FDA describe elevated haematocrit in dogs given Metronidazole. That is 0.8% of all reports for this medicine, compared with 0.0% across reports for all dog medicines, so it is reported unusually often with this medicine.

26Reports

88%Marked serious

12%Recovered

19%Died or euthanised

14 daysTypical onset

How soon it started

Same day

3 13%

1–2 days

4 17%

3–7 days

2 8.7%

1–4 weeks

4 17%

Over a month

10 43%

How the animals did

Recovered

3 12%

Still unwell when reported

10 38%

Died

3 12%

Euthanised

2 7.7%

Not known

8 31%

Problems reported at the same time

21 81%

16 62%

16 62%

15 58%

13 50%

8 31%

8 31%

7 27%

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 elevated haematocrit in dogs?: 26 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 14 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).

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