If you have decided definitely on rehoming him, you're right not to put him in the paper (or online equivalent). I would ring one of the breed rescue societies for advice - they often have fosterers around the country so he would not need to go into kennels.
Is he a King Charles or a Cavalier King Charles? (Just that they have different breed rescue societies). Numbers below.
King Charles Spaniel Rescue
Mrs B Wigzell, Brighton, Sussex. Tel: 01273 593296
Mr D Wickens, Ammanford, Dyfed. Tel: 01269 825716
Email: [email protected]
Cavalier King Charles Spaniel Club Welfare and Rescue Service
Mrs J Pagan (Co-ordinator), Wickford, Essex. Tel: 01245 320488
Humberside Cavalier King Charles Spaniel Club Rescue
Mrs L Flynn, Nr Boston, Lincs. Tel: 01205 760374
Midland Cavalier King Charles Spaniel Club Rescue
Mr & Mrs R Rees, Coventry. Tel: 02476 403583
South and West Wales Cavalier King Charles Spaniel Club Rescue
Mr and Mrs Harris, Newport, Gwent. Tel: 01633 680315
Southern Cavalier King Charles Spaniel Welfare Organisation
Mrs C C Li (Co-ordinator), Herts.
Tel: 020 8905 2621. Email: [email protected]
www.cavalier.info/clubs/southern/welfare.htm
West of England Cavalier King Charles Spaniel Club Welfare Scheme
Miss C G Greenall, Nr Kingsbridge, Devon. Tel: 01548 580369