Lymphopenia after Enrofloxacin (Baytril) in cats

28 reports to the FDA describe lymphopenia in cats given Enrofloxacin. That is 1.8% of all reports for this medicine, compared with 0.4% across reports for all cat medicines, so it is reported unusually often with this medicine.

28Reports

61%Marked serious

7.1%Recovered

54%Died or euthanised

8 daysTypical onset

How soon it started

Same day

3 21%

1–2 days

3 21%

3–7 days

1 7.1%

1–4 weeks

3 21%

Over a month

4 29%

How the animals did

Recovered

2 7.1%

Died

4 14%

Euthanised

11 39%

Not known

11 39%

Problems reported at the same time

16 57%

13 46%

12 43%

11 39%

10 36%

9 32%

9 32%

9 32%

Age of the animals

Under 1 year

1–3 years

4–7 years

8–11 years

12+ years

About this medicine

Enrofloxacin treats bacterial infections.

Products with this ingredient include Baytril. The FDA hides brand names in its public data, so these reports cover every product with the same active ingredients.

Questions owners ask

Can Enrofloxacin cause lymphopenia in cats?: 28 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 8 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).

Lymphopenia with similar medicines

Lymphopenia after Cefovecin (Convenia) 122 reports · 1.4% of its reports

All reported side effects of Enrofloxacin in cats · Medicines most reported with lymphopenia