Well, It has been 3.5 weeks, and this is what we have done, and this is our progress.
Heart worm tested, came back neg.
Keep in mind he gets to free run for close to 4 hours a day (as in he has about 20 acres that he chases birds around), it is not uncommon for him to accompany us on a 30 minute bike ride as well.
We tried increasing his food to 4 cups a day for a week. He actually lost weight. We then upped it to closer to 5 cups, and gave treats freely I also threw in a couple satin balls for good measure. There was more than once in there that we actually double fed breakfast because my wife and I forgot to tell the other they had already fed him. Which means an extra 2 cups on those days. We were able to get him to gain a pound that week. We continued that same process (without the double feeding) of around 5-6 cups a day plus treats. We were able to put another pound on him.
So grand total after the three weeks, is he is 1.2 lbs up.
Our next step is we have ordered a higher calorie food for him to see if we can get him more calories with less cups of food.
Should I just ride this thing out and see if it is an age thing? He is a year old this week.