As already said, each dog does best on a different kibble. Dempsey does best on a grain free kibble whose protein isn't super high (below 30
. Other dogs do better on a high protein kibble. I like kibbles that don't have a whole lot of different ingredients in them. I would change slowly so as not to make the situation worse.
Taste of the Wild (TOTW) Pacific Stream
Acana Pacifica
Wellness Simple Grain Free (Turkey and Potato is rated the highest of these)
Blue Buffalo (BB) Freedom
Earthborn Grain Free
If you change to a grain free, you'll feed less of it (over feeding it will cause loose poo), and you'll see smaller stools.
If your dog has trouble after switching, try a different protein source. Some dogs for example, have trouble with chicken based kibbles.