Puppy bathroom habits

Question
I have a 5 1/2 month-old puppy, mixed breed (shepherd/husky/lab/some kind of hound.) He was a rescue dog, came up to Boston from Tennessee.  I've had him less than 3 weeks.  He is the sweetest thing, but he poops a lot!  We had our vet check and I told them he poops 4 times a day.  They were not concerned.  He is on meds for parasites and had a one-dose wormer this past week, so he's been drinking and pooping even more, 5 sometimes 6 times a day.  He eats high quality food.  His foster was feeding him Eagles Holistic chicken and rice for puppies, and I'm transitioning him to Blue Buffalo brand.  He has had soft stools since I've had him.  The vet thinks that once the meds are done, that should help, but if not they can give him something to rebalance his system (not sure what that would be.)  He also passes gas a couple times a day.  He isn't eating canned or people food, just dry dog food and hard treats. It's been a  while since I've had a puppy so I'm used to dogs who poo once a day.  I feel like I'm forever picking up poo in the yard, and I can't believe how much comes out of him on a daily basis!  Does all this sound normal to you?  Interested in a second opinion.

Answer
How much are you feeding him?  There isn't any chow that is right for all dogs.  I mostly feed Pro Plan, and seldom have had problems.  I did have to feed my one Lab about 6 cups, twice what most of them need.  Perhaps I should have done something, but I didn't.  If the Blue Buffalo is chicken too, you might try something else, perhaps a lamb or beef.  

It is also possible once he get off the medicine and stabilizes, he will do better.  You might stick with the Blue Buffalo until then.