My dogs are actually on a high quality fresh frozen diet of meat, fish and vegetables, but they do get a small amount of rice since I mix this with chicken and vegetables in stuffed kongs. A lady on a group that I follow (for rescue dogs) told me not to use rice in kongs because it has "no nutritional value". I googled and found a wide variety of references to the contrary, shared this with her and she responded that she was qualified in dog nutrition (probably got a diploma in dog nutrition where the entry requirements are a GCSE English language - wow, hold onto your hats!)
Anyone found anything definitive on this? Preferably from an academic journal?