Lethargy after Feline Core Vaccine in cats

695 reports to the FDA describe lethargy in cats given Feline Core Vaccine. That is 45% of all reports for this medicine, compared with 14% across reports for all cat medicines, so it is reported unusually often with this medicine.

695Reports

54%Marked serious

35%Recovered

15%Died or euthanised

2 daysTypical onset

How soon it started

Same day

188 28%

1–2 days

159 24%

3–7 days

96 14%

1–4 weeks

181 27%

Over a month

42 6.3%

How the animals did

Recovered

240 35%

Still unwell when reported

269 39%

Died

54 7.8%

Euthanised

49 7.1%

Not known

83 12%

Problems reported at the same time

474 68%

297 43%

212 31%

105 15%

100 14%

85 12%

81 12%

79 11%

Age of the animals

Under 1 year

220

1–3 years

174

4–7 years

150

8–11 years

103

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 Core Vaccine cause lethargy in cats?: 695 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).

Lethargy with similar medicines

Lethargy after Rabies Vaccine 884 reports · 34% of its reports
Lethargy after Feline Leukemia Vaccine 322 reports · 40% of its reports
Lethargy after Distemper-parvo Vaccine 63 reports · 23% of its reports
Lethargy after Chlamydia Psittaci Killed + Feline Core Vaccine 31 reports · 55% of its reports

All reported side effects of Feline Core Vaccine in cats · Medicines most reported with lethargy