no no no.. damn it.. we started this together/same time !!!! I remember the day you posted and I was gna post the same thing.. I thought YAYY, We're starting it together..lol (I know, ima goof.. ) Our dogs are sim. in age even. IDK, Hafta see what others say. I would think that if you did some ultra* light it would be same as running around.. but again..idk. Kinda like when i was in school, Had a doctors appointment.. They told my mom i had a heart Mur Mur... They suggested that my mom pull me outta my sports (Softball,Cheerleading and Swim Team ). I laughed really loud and my mother smacked me on the face and said 'this isnt funny' I never did get pulled from my sports. Then again.. its prob. not even close to the same thing for a dog. Im really sorry that you are haviin to go thru this with such a YOUNG boy!! He is only 2 ish right?