Teach a dog how to swim
I thought this was instinct, that all dogs could do the 'doggy paddle'. Obviously not.
Out walking in the woods this afternoon my boxer picks up the scent of something and follows it down a steep muddy bank that neither of us can get back up. Only way out is to cross the river. I wade in and the dog follows and sinks to the bottom, makes no attempt whatsoever to swim or keep her nose above the water. I had to carry her across the river over my shoulder.