We cruised with a great small dog we picked up in Mexico
(as a puppy) for 3 years. It was a hassle, though the dog loved it. Then when we moved ashore and she discovered squirrels, carpet, and sofas, she hated sailing.
As much as I love animals
, I believe long term cruising
with them is too much hassle (officials, shots, vets, potty breaks, injuries, fleas, other dogs
, etc..) and can seriously detract from a cruise