My German Shepherd is 8 months old and has been eating great up until about 2 weeks ago. He was eating 3 cups of kibble a day and we realized he should be getting more food. So we start feeding him 6 cups a day. For about the first week he ate everything possible. Now the last 2 weeks he bearly will eat anything. We tried putting turkey gravy into his food and also wet canned food in also. But he will not eat hardly anything. He is drinking a normal amount of water and he is having normal bowel movements. He likes to go for walks on a normal basis.( about 2-4 miles a day).Anyone have any idea what is going on? Thanks.