Companion Animal Welfare

Cat Vaccination Side Effects Welfare

Vaccination reactions in cats range from mild self-limiting signs to rare serious adverse events requiring awareness and monitoring.

Key Facts

Most cats show only mild local soreness at the injection site after vaccination
Lethargy and reduced appetite for 24-48 hours is normal and does not require intervention
Hypersensitivity reactions including facial swelling and urticaria require emergency veterinary treatment
Injection site sarcoma is a rare but serious long-term complication of adjuvanted vaccines
Pre-vaccination health checks ensure only healthy cats receive vaccination

Welfare Considerations

Vaccination benefits far outweigh risks for the vast majority of cats, but awareness of potential reactions allows prompt treatment when needed. Monitoring cats for 30-60 minutes post-vaccination enables rapid response to hypersensitivity reactions.

What You Can Do

Monitor your cat for 30-60 minutes after vaccination for signs of hypersensitivity reaction
Return for emergency treatment if facial swelling, vomiting or collapse occurs after vaccination
Report any suspected vaccination reactions to your vet and to the Veterinary Medicines Directorate