Bad gas

Question
Hi there Jennifer, wondering if you could please give me some advice on what to do with boxer boy - he produces the most smelly gas ever, along with pretty loose poops.  We started adding natural yoghurt to his food but it has made no difference.  We tried quite a few different kibbles/wet foods, including James Wellbeloved, Burns and Wainwrights.   We currently have him on Orijen - as it is carbs and grain free, but this has made no difference either. Raw feeding/home cooking is not an option we wish to consider.

I have been doing some of my own research on the internet and it seems like he could need some probiotics but I don't really understand them - how they work? and which would be the best type to give him? and also in what way would probiotics be any different to what he gets in the natural yoghurt?  The only other thing I found on this area was charcoal, do you know how that works and would it do him any harm to have it? Thanks for your time.

Answer
While some dog foods don't work with some dogs, the problem could be parasites.  Take a fecal sample to the vet.  You may even have to have more than one test done.  Until any parasites are identified and remedied, no diet may work.  

Probiotics can reintroduce good bacteria without the excess calcium in yogurt.  You don't want to give any large breed less then 78 months old too much calcium.  It can do more harm than good, wrecking the dogs hips.