Lethargy after Metronidazole in dogs

The FDA has received 798 reports of lethargy in dogs after Metronidazole. That is 26% of all reports for this medicine, compared with 11% across reports for all dog medicines, so it is reported unusually often with this medicine.

798Reports

69%Marked serious

15%Recovered

29%Died or euthanised

6 daysTypical onset

How soon it started

Same day

150 22%

1–2 days

129 19%

3–7 days

99 14%

1–4 weeks

131 19%

Over a month

185 27%

How the animals did

Recovered

112 14%

Recovered with lasting effects

10 1.3%

Still unwell when reported

335 42%

Died

89 11%

Euthanised

139 17%

Not known

113 14%

Problems reported at the same time

503 63%

450 56%

407 51%

281 35%

228 29%

154 19%

148 19%

132 17%

Age of the animals

Under 1 year

110

1–3 years

145

4–7 years

186

8–11 years

201

12+ years

151

About this medicine

Metronidazole treats some bacterial and parasitic gut infections.

Questions owners ask

Can Metronidazole cause lethargy in dogs?: 798 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 6 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).

Lethargy with similar medicines

Lethargy after Amoxicillin + Clavulanate (Clavamox) 1,070 reports · 20% of its reports
Lethargy after Doxycycline 677 reports · 17% of its reports
Lethargy after Cefovecin (Convenia) 936 reports · 25% of its reports
Lethargy after Enrofloxacin (Baytril) 795 reports · 21% of its reports
Lethargy after Amoxicillin 344 reports · 26% of its reports

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