Do you know Cost-co dog food?

Ok, so my confimation coach who breeds and show bull mastiff said he feeds his dog cost-co dog food, He said that the ingrediants are great. I was wondering, I am going to go join Cost-co today because of this, Does anyone know if this is good food or not? I ume he knows what he is doing, But I went on their webpage to see the ingrediants but they don't have the food up there..Any one know if this is good food or not- >?