What Breed is my Pit Mixed With?

My dog is a 26 inch tall, 71 lb. male Pit mix. He had webbed toes and longer ears than a Pit. His muzzle is longer than a Pit as well. We are going to do a DNA test soon, but I wanted to see if anyone had any thoughts.

His coat is wiry instead of soft and silky and he has dark chocolate tones. This dog is only a year old. He will continue to grow and put on some more weight. He is very calm and sleeps often. He does drool as well. There is some loose wrinkles of skin around his neck and all around his body. What do you think?