According to their website "The service is only offered on scheduled Transatlantic Crossings between New York and Southampton or Hamburg. The Cunard Kennel service is ideal for guests who are moving to or from the United Kingdom or Europe, as the Kennel allows you to make the process of pet quarantine more comfortable. Very strict regulations apply and you must start preparations at least six months before departure to ensure you have all steps, including implanting of a chip and rabies shots, completed. The limited number of kennels makes it essential that you reserve far in advance."
Check out their dog blog @ http://wearecunard.com/2010/02/it%E2%80%99s-a-dogs-life-on-the-north-atlantic/