QUESTION: Occasionally we see poodles who want to bottom walk while they paddle their front legs. In your opinion is this a structural problem?
ANSWER: What you describe is typical of dogs who did not learn to swim at a very early age, not a structural problem. The dogs panic and thus end up nearly upright and nearly sinking. I've reeducated several dogs to a better form of swimming with hands on work, literally lifting the rear as they swam; also, lots of work on confidence building - in my experience, dogs that do this are often quite impulsive, not as confident as they could be, and rather emotional. Getting them to think while a bit worried is worth the effort.
There are doggy lifesaving jackets that keep the dog in the ideal position for swimming. This may help some dogs. Other designs make things worse for the dog, so be careful.
But I've had the best luck getting in the pool or lake with the dog and working slowly, in small successful steps. What I always want with any dog is that if I support them, they will trustingly lay in my arms. For whatever reason, this seems important to the thrashers!