Wow, I missed this one earlier. Is that a kettlebell of some sort in his mouth?
He looks so much like our dog Jazz! We just lost her to bone cancer this past September. She was the best dog, got her from the pound at about 5 months of age. Here she is at about age 1 or 2, and then about 12 as an old lady. She was a sweetheart... Don't know what mix of breeds she was, but we suspect some Blue Heeler, some terrier, maybe some Australian Sheppard. Dogs are great.