I would take in a second stool sample to once again rule out the possibility of parasites, Coccidia and Giardia. If tests come back clear once again, you may want to go back to feeding solely Eukanuba for at least a couple more weeks. It can take several weeks for a pup to fully adjust to a new enviorment and unsettled nerves can cause stomach issues to begin with, adding a new food on top of everything else may just be the straw that breaks the camels back. Once you have a stable routine down, then begin the slow transtion to the new food. Or given the fact that Freedom is Grain Free whereas Eukanuba is grain inclusive and mixing the two may very well be what is causing the issue, you could try feeding the last meal of the day as Eukanuba and being the next day with solely Freedom. Some stomach upset may occur but should clear up within a couple of days. Also, try feeding 1/4 of a cup at a time rather than 1/3. Grain free foods have a tendency to be richer than grain inclusive foods and overfeeding is a big contribution to irritable digestive systems..