Good age to hike 4 or so miles

[Shianne Mack]

So my pup will be 7 months in about a week and I wanted to know if it would be okay if I start taking him on some more difficult hikes. I hike with him every weekend (on different terrains and everything) but I never go the full way. I usually stop at almost mid point then head back. He never really seems too exhausted to where he can't walk anymore, so I am wondering if I could start taking him on longer hikes now. I love to hike, so I can't wait until he is able to go the full distance with me. I just don't want to push him if he is too young.