I got Ranger when he was approx 9 months and he was too skinny at 66 lbs. You couldn't see his ribs because of the long hair, but you could easily feel them and the spaces between. He was 72 lbs in the summer/fall and was in great shape. Running 3 miles a day with me plus 2 hour walks a day. Now he's at 75 lbs and is getting a little plump. He's not overweight, but he's not the lean body type he should be. Gotta start running again!