Running an Aussie

Question
I have a 10 month old Aussie.  Is it too early to take him jogging or on the trails when I mountain bike?  Most of what I read says to wait until puppies are 12-14 months, but my breeder said that Aussies were a little different and it'd be alright to take him now.  He seems to love it and he isn't on a leash so he could go at his own pace, but of course he stays right with me.  Are there risks I should be worrying about?

Answer
At your dog's age, if you are going for about 20-30 minutes of reasonable exercise, and your dog does not show any signs of exercise intolerance or a lack of wanting to go with you, then some jogging or biking is probably ok (I hope you are using a springer on the bike and not letting your dog jog loose).  I would be concerned about the surface you plan to jog on, as you don't want to have impact injuries or damage to the young and tender pads.  And, you don't want to overstress young tendons and ligaments.  But, your breeder is right in the sense that Aussies, being a medium sized breed, and designed for stamina while working, are less likely to get in trouble than large breed puppies of the same age.