Just a side note because I haven't seen it mentioned...you do know to never run after the dog, right? That only makes then run further away because they think that you are playing their game.
I'm thankful for a fairly large fenced back yard. Wallis fell in the pool the first night we were here - it was on her blind eye side and she didn't see it. But she swam for the steps. I have purposely put the other dogs in the pool just to make sure they know what it is and hopefully would know which way to swim if they were to fall in.
Good luck - I know how aggravating it can be when they won't come on command. That's when you have to remember that you are human and he is a dog.
RIP Wallis, John Robert, Tibby & Pip
Mom to JoJo, Roxie & Linguini (Cavaliers)
and my birds Moji (Senegal) and Walter (Blue Front Amazon)