Blood problems after Feline Leukemia Vaccine in cats

The FDA has received 48 reports of blood problems in cats after Feline Leukemia Vaccine. That is 6.0% of all reports for this medicine, compared with 1.9% across reports for all cat medicines, so it is reported unusually often with this medicine.

48Reports

83%Marked serious

23%Recovered

35%Died or euthanised

5 daysTypical onset

How soon it started

Same day

10 23%

1–2 days

9 21%

3–7 days

5 12%

1–4 weeks

12 28%

Over a month

7 16%

How the animals did

Recovered

10 21%

Recovered with lasting effects

1 2.1%

Still unwell when reported

18 38%

Died

4 8.3%

Euthanised

13 27%

Not known

2 4.2%

Problems reported at the same time

36 75%

29 60%

16 33%

14 29%

12 25%

12 25%

10 21%

10 21%

Age of the animals

Under 1 year

1–3 years

4–7 years

8–11 years

12+ years

About this medicine

Type: vaccine.

Mild, short-lived lethargy, soreness or a small lump at the injection site are the most commonly reported vaccine reactions.

Questions owners ask

Can Feline Leukemia Vaccine cause blood problems in cats?: 48 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 5 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).

Blood problems with similar medicines

Blood problems after Rabies Vaccine 117 reports · 4.5% of its reports
Blood problems after Feline Core Vaccine 117 reports · 7.5% of its reports

All reported side effects of Feline Leukemia Vaccine in cats · Medicines most reported with blood problems