I'm with Kerry, any dog with an athletic type build will make a good fishing dog. I've had a Catahoula that I picked up at a rescue in Montana for a few years now. They're notorious game chasers, but I usually don't fish places where that's going to really get him into trouble, because I like bringing him along. A dog should be able to go chase some critters while you're chasing fish. And his antics have turned into some of my favorite fishing memories. If you're thinking in the 30-50 range, I think that's the criteria for a fishing companion. Dogs are rad.