I'm erring on the side of agreement, except in a case where the breed (I'm totally un-educated on this area) was suited to lots of swimming. I'm told something Spanglish might be great for this.
I have a water-loving dog (labrador retriever), but she cannot swim from my boat, and I doubt most dogs could enter and exit the water from most sailboats--forgetting about currents and swell. So, you'd be passing the dog into a dinghy, to get to shore, to swim. And that's only an option in ideal conditions in a good anchorage. Your dog will be miserable on passages, if not terrified by the movement of the boat. Many get sick just riding in a car.
SE Asia? Gonna be hot. Do you have AC on the boat? What do you do when you need to dinghy into the laundromat and grocery store, or want to do some sightseeing on land? Your pet will die locked in the cabin in 90+ degree weather. Someone will always have to have the pet, which really hinders what you can do off the boat.
If the point of cruising is to get out and see and experience the world via sailboat, a pet is not an ideal companion.