Lethargy after Cefazolin in dogs

The FDA has received 119 reports of lethargy in dogs after Cefazolin. That is 28% of all reports for this medicine, compared with 11% across reports for all dog medicines, so it is reported unusually often with this medicine.

119Reports
81%Marked serious
21%Recovered
46%Died or euthanised
3 daysTypical onset
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How soon it started

Same day
17 17%
1–2 days
24 24%
3–7 days
22 22%
1–4 weeks
22 22%
Over a month
16 16%

How the animals did

Recovered
25 21%
Still unwell when reported
32 27%
Died
25 21%
Euthanised
30 25%
Not known
7 5.9%

Problems reported at the same time

Age of the animals

Under 1 year
17
1–3 years
24
4–7 years
48
8–11 years
27
12+ years
2

About this medicine

Type: medicine.

Questions owners ask

Can Cefazolin cause lethargy in dogs?
119 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 3 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

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