Hair loss after Feline Leukemia Vaccine in cats

The FDA has received 69 reports of hair loss in cats after Feline Leukemia Vaccine. That is 8.6% of all reports for this medicine, compared with 14% across reports for all cat medicines, so it is reported less often than average with this medicine.

69Reports
64%Marked serious
36%Recovered
4.3%Died or euthanised
2 daysTypical onset
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How soon it started

Same day
10 16%
1–2 days
23 36%
3–7 days
16 25%
1–4 weeks
10 16%
Over a month
5 7.8%

How the animals did

Recovered
25 36%
Still unwell when reported
12 17%
Died
1 1.4%
Euthanised
2 2.9%
Not known
29 42%

Problems reported at the same time

20 29%
16 23%
Skin rash or irritation
8 12%
6 8.7%

Age of the animals

Under 1 year
6
1–3 years
28
4–7 years
17
8–11 years
14
12+ years
4

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 hair loss in cats?
69 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 2 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).

Hair loss with similar medicines

All reported side effects of Feline Leukemia Vaccine in cats · Medicines most reported with hair loss