soft stool in puppy

Question
I have a 6 month old standard poodle puppy. On the advise of his breeder I have started feeding him adult dog food.  I slowly converted him from Pedigree Puppy to Wellness chicken.  His stools always were soft in comparison to my 6 year old standard poodle.  But now that he's on Wellness alone they resemble cow patties!  He is gaining weight as he should, and as active as any 6 month puppy should be.  I began mixing white rice with the Wellness about 3 days ago.  No change.   Should I change to the Wellness Lamb?  Should I put him back on Pedigree Puppy?
P.S. He is clear of parasites per vets' tests results

Thanks!
Tina and Rommel

Answer
Well first he needs to be on large breed puppy food until 1 year of age.  Second its entirely possible that he is still teething and that is why he has soft stools.  The molars take longer to come in than the rest of the teeth.  I would look in his mouth and see if you can see any signs of teething.
Could also be that he is not doing well on the food.  Some dogs systems are very sensitive.  I would put him back on the puppy that he was doing so well with and see how the stool is after that and go from there.  Remember when shifting him back to the puppy food that it could take 1-2 weeks for his system to adjust again and return to normal.  There are also several lamb and rice puppy foods out there that are really better quality than pedigree.  You might check with Petsmart or petco and see what puppy food they have for large breeds.  Be sure to stay as far away from Corn and Wheat products in the food as this is what most dogs have reactions too.  If Wellness has a puppy food you might try that.