[adorno]

The dolphing were probably effing with the dog, not saving it...

Was thinking the same thing.

The dolphins were probably the ones that kept the dog out in the canal for so long, trying to have fun while doing so. Then, when they finally got bored, they signaled for somebody to come get the dog out.

[JoeProBono]

[Salamander]

You are very likely right.

Dobes are -notorious- for being bad swimmers and won’t swim unless they have to.
[Too narrow/keel-shaped and no buoyant body fat or fluffy fur.]
They can’t easily stay upright in the water like a Lab [or every other water dog] can.

Most people who take their Dobes swimming use special doggy flotation vests.