I've had my GSD for a little over a year now. He is about four years old. Over the past 2-3 weeks his appetite has diminished. He used to scarf down two cups of Blue Wilderness in the AM and two in the PM. We've been doing a lot of exercise the past several months - anywhere from 3-8 miles per day of running/walking/jogging. He always eats laying down. I'm spending significant time every morning and night trying to get him to eat. I feel like a cheerleader cheering him on and trying to coax him. He seems to mostly skip any AM feeding and will eat at night now so I try to feed him before our big run and later on in the evening (being careful to leave enough time to prevent bloat). I'd say out of the four cups of food he used to consume in a day he now consumes 2.5-3. I'm wondering if its normal for an adult dog to lose some appetite in the summer? He is getting a lot of exercise so I'm worried.