A few weeks [like 3-4?] isn't that long for a dog to get used to if they have a sensitive stomach. It took my greyhound closer to 8-10 weeks to get settled on the biscuit i'm giving her. One's judge is the coat and No: 2s. The No: 2s gradually got firmer and firmer. I don't know what dry complete does to a dogs digestive system but they do need a bit of time to 'detox.' I a dog is used to bit of change and is young like my lurcher it doesn't matter so much it seems.

Let me know what sort of grinder you get - i've been after one myself.