You can get a lot of Info from your dogs poo
The problem I had, or my dog had, from using a local retailers own brand, was that his stools varied a lot from day to day on what they looked like. It didn't matter whether I gave him treats or not, it varied a lot when it was like he had full diarrhoea or even partial diarrhoea with slime in the form of a skin around some of his stools. It used to happen intermittently, But since using Arden Arms Adult Chicken and Rice he has no problems since even with the treats we used to give him.