Given the way dogs are jointed, I suspect the dog paddle is pretty much the only kind of swimming they can do, and it's basically the same movement as walking, which is certainly a learned activity. The coordination takes some effort. And that you can do it at all without drowning is not intuitively obvious. And the human in the water encouraging them to come to him probably facilitates it, if the pups trust himl. AAas far as I can see, only two of the pups put all the acts together and end up swimming. It's not instinctive, or not totally. It takes some learning on the pups'part.
When I was a kid, one of the schools of instruction in learning to swim was basically, when you thought the kid was of age, you'd just pick them up and throw them in, no instruction, sink or swim. Some kids jjust sank. My uncles had a fruit farm with a lovely lake, where we all learned to swim. Some of my cousins were thrown in. My parents were a little less draconian/ But I still was a fairly slow learner in dog paddling. Posted a video here a while back of a baby otter learning to swim, and he definitely was on a learning curve. His mom was not dissimilar to my uncles--she grabbed him by the scruff of the neck and flung him in.
On another note, after the Boston Marathon bombing,the cops came to Red Sox games with bomb-sniffing dogs, one of which was a long-haired German Shepherd. I didn't know they came that way. It looked like a cross between a teddy bear and a dog. Here's the hairiest one I could find on Google, but the one at Fenway made this one look almost bald, it was so furry.
Squirrels are famous for stealing food stuff out of your cart also...
