If you say you know hes that old then I guess he is but he sure doesn"t look to be at least 4.5. He has a pot belly that comes with 3.5 yr old but no sway in his back and a very thin chest. He also has alot of muscle seperation like a young deer generally does. If I seen him for the 1st time without any of your info I'd have said 3.5 tops.