I think the moot point is on the issue of where the 'disturbance' begins: For many dog owners who are used to pet their dogs, scratch their bellies while they're eating and even kiss them on their mouth (I live in NY, I see quite a lot of this ), it may be "oh but so normal" to have their 'babies' running around unattended on a poolside bar - but that someone who is about the start eating their salad may not appreciate the canine presence right under their table trying to sniff their pants, in fact they may find it outright repulsive.

The same goes for the customers who are disturbed by incessant barking - the sound which may sound "so lovely" to the pet owner may be extremely disturbing for someone else.

I liken this to smoking in a sense - for a habitual smoker, that repulsive smell is something they are quite familiar and happy with, but there are clear rules in place to ensure that it does not harm others. Could the same approach work for pets? Pet-only floors in a hotel maybe, where you would be allowed to leave your dog unattended in your room during daytime hours and it could bark all it wants. Or pet-only rooms in a hotel restaurant which allows pets in, while at the same time ensuring that other petless customers are saved from the myriad health hazards and unpleasant encounters?

In either case however, I would be extremely surprised if any hotel establishment anywhere in the world did not hold Guests fully responsible to the maximum extent "if excessive damage or deep cleaning is required". The canine defecation stain on a room carpet or the part of the sofa upholstery that has been chewed into oblivion should obviously remain a guest responsibility.