Items listed farther down the ingredient list are a small percentage of the whole package. Vitamins and minerals only account for 1% of the total weight. With the exception of pre-biotics and pro-biotics, which are fiber and micro-organisms intended to aid in digestion, anything after the vitamins and minerals is insignificant.
Ingredients are listed in order by their weight. Items listed first have the most weight. For a food to be considered a "meat-based diet", the meats must be listed first on the ingredient list. For example, consider: "Turkey, Chicken, Chicken Meal, Barley, and Oatmeal". In this example, "Chicken" would be listed before "Chicken Meal" as the only difference between the two is that "Chicken" refers to the type of chicken you'd buy at the grocery store and "Chicken Meal" is simply dehydrated chicken where the water has been removed. "Chicken" would weigh more than "Chicken Meal", so it is listed first.
In What Order Are The Ingredients Listed?
The meat should always be listed first. In fact, the first 3 ingredients should be meats, unless it is a single source protein diet. In that case, you may only see one type of meat listed, perhaps in both hydrated ("Chicken") and dehydrated ("Chicken Meal") forms. The other exception is when the food is considered a limited ingredient diet.
Be cognizant of the ingredients listed after the meat/s. If several forms of grains or carbohydrates are listed, that can diminish the overall percentage of meat. For example: "Rice, Rice Flour, and Brewer's Rice". In this example, the overall weight of the rice, since those are all technically "rice", may be more than the meat, thus decreasing the nutritional value of the food. Pet food companies frequently break the grains down to make them appear to be only secondary ingredients, when in reality, they are the primary component of the food.