Ash

Ash is the mineral content of a dog food, measured by burning the food and weighing the inorganic residue. Most adult maintenance recipes run 5 to 8 percent ash. Higher ash usually reflects higher bone meal or mineral supplement content. Very high ash (above 10 percent) can be a sign of low-quality protein sources with excessive bone fragments. The term 'ash' on a label is a chemistry artifact, not an additive. There is no actual ash in your dog's food. The number tells you what would remain if everything organic burned away.