Here at Just Dogs we strongly promote reward based training but understand that for some dogs it can be tricky to find the right treat to motivate them, with some dogs being more fussy / less 'food motivated' than others. This article from Eileenanddogs helps explain why some dogs may seem less keen to take / work for treats than others and gives helpful tips for using food in training: http://eileenanddogs.com/2016/06/14/