Learning to run with a dog?

So I'm 6 months out from surgery with 140 lost total (about 40 was pre-op weight) . I still have about another 80-100 to loose. I'm going to consult my doctor before I attempt any sort of running program (I plan on the couch to 5K) just to make sure. I figure by spring I should be down enough to not hurt myself and be able to do it.

I have a big goofy dog that LOVES to run and be outside. I want to jog with him, but have no idea how to train him to understand. I went from sitting on the couch everynight with him to walking him 2+ miles, and he loves it. I want to continue to include him in my workouts but I'm concerned he wont get that he cant stop and sniff, lunge at another person ect. He's really good on walks, but I have to kinda stay on him to keep him that way. He is such a social butterfly he forgets about me and wants to say hello to everyone. Has anyone had a dog like this that they trained to run with them?

My thought was that I would start the program with him so he could build the endurance with me since hes never been taken jogging before. My concern doing that though is I might have to be more focused on what hes doing that what my times are and focusing on my breathing ect.

Any ideas?

I volunteer at our local Humane Society, where I walk/run the many different dogs.  What I've found that works best is a shorter leash, so they're not as easily distracted.  In the first block or so, I let them sniff and do their business.  Then, I shorten the leash and pick up the pace.  If they start pulling on the leash, I come to a complete stop until they stop pulling.

I'm always working with different dogs at the Humane Society.  Yours will eventually learn what you expect with patience and consistency.

Cassie