Weight loss after Metronidazole in cats

62 reports to the FDA describe weight loss in cats given Metronidazole. That is 16% of all reports for this medicine, compared with 4.6% across reports for all cat medicines, so it is reported unusually often with this medicine.

62Reports

58%Marked serious

4.8%Recovered

21%Died or euthanised

7 daysTypical onset

How soon it started

Same day

10 20%

1–2 days

10 20%

3–7 days

7 14%

1–4 weeks

14 27%

Over a month

10 20%

How the animals did

Recovered

3 4.8%

Still unwell when reported

29 47%

Died

3 4.8%

Euthanised

10 16%

Not known

17 27%

Problems reported at the same time

31 50%

31 50%

17 27%

15 24%

12 19%

11 18%

Ketosis

11 18%

Liver problems

10 16%

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 weight loss in cats?: 62 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).

Weight loss with similar medicines

Weight loss after Cefovecin (Convenia) 768 reports · 8.8% of its reports
Weight loss after Amoxicillin + Clavulanate (Clavamox) 139 reports · 5.8% of its reports
Weight loss after Enrofloxacin (Baytril) 60 reports · 3.8% of its reports
Weight loss after Amoxicillin 39 reports · 7.6% of its reports
Weight loss after Doxycycline 28 reports · 11% of its reports

All reported side effects of Metronidazole in cats · Medicines most reported with weight loss