
Some of the Forthglade products are a "complete" and ballanced meal in itself, you may un-ballance the menu if you add a mixer. No furthur mixer needs to be added.
Other Forthglade products are meat alone, and although assorted meat, bones and offal will produce a naturally ballanced diet
a good quality mixer such as the "Natural Choice" that you have mentioned will do no harm at all.
I sometimes add a little natural Choice to my girls "raw" diet, it never upsets their digestive systems, their poo's stay dark and firm too. A lovely choice of mixer !