I am guessing this is one of the world's happiest dogs! I have a dog that LOVES to chase balls. That was him on the picture you clicked to get to this story. He would do it until he literally can't walk any longer. I have played fetch with until I thought my arm was going to fall off and he was still ready for more. I am thinking I need to build something like this. However, I think my dog would do this until it killed him! How long do you think this pooch does this, I am betting its about ALL DAY!