feeding an active

[shaggy_dog]

I'll try to make this short. Sully was once over weight. weighed 50lbs in June. Changed his food to reduced fat evo started running him 5k 5 times a week and he now weighs 38lbs. He is an active dog terrier mix. We moved to AZ but will be moving back to MI soon. But while we are still here he is going to be very active. I know when I move back the cold will stop a lot of this. Today I ran him 5k (3.2miles) and then walked him and molly 2.5 miles. Molly won't walk without sully and she won't run with us so I have to do 5 miles 5 a week. So today on top of this my parents took him on a hike that was 3.5 miles long. So he did 9 miles today. He's tired but still has the energy to bark at the neighbors right now Usually on sundays we go on a long hike about 7 miles.
So my question is besides increasing his food should I be giving him something else? I know when I do long hikes I eat goo for energy. I do take about 1/4 cup of his food with us on long hikes. He has a very sensitive stomach and it's hard on him and my noise when i switch it. I have tried to give him some of molly's food only about 8 pieces to increase his calories but he gets diarrhea. I don't want to switch his food cause i know this activity level will not stay this high only for another month. He's maintaining his weight and not losing anymore. So do you think just increasing his food is ok. or is there something they give to hunting dogs and working dogs?

[sarahliz]

If he is doing well and has had food issues in the past I say stick with what you are doing. Do you know what his issues were (grains etc)? You could also try "Zukes Power Bones" on really long hikes/runs, they are basically doggie power bars and are wheat/corn/soy free and come with different protein options so you might find something that works. I used their mini-treat for training because they stink like hell going in (and what more does a dog want?) and not so much going out AND my parents dogs super duper sensitive system didn't go all haywire on them!