Since you are in London, why don't you go through any of the large parks during the day. You will surely run across dog sitters there. I see them at Holland Park, Kensington Gardens, Battersea, Hyde Park..They are usually the people walking about 10 dogs at a time and they usually charge about £10 a day per dog. You may also want to check your Vet and local Pet Stores usually post sitters as well.
