Pet food labels are not required to meet the same standards as human food labels and lack a good deal of consumer-friendly, useful information. Even the ingredient lists on pet food labels is only moderately useful. One really vital thing to understand? Dry Matter Basis (DMB). This refers to the amount of an ingredient expressed as a percent of the total solids in the can or bag if the moisture is removed.
Once you understand DMB, you can compare dry and canned foods in an apples-to-apples kind of way. Here’s how it works:
- Dry food has about 10 percent moisture. This means that everything else is 90 percent of the food. So the math goes like this: if you see protein listed on kibble as 20 percent, divide by .9 to get 27.7 percent. So dry food with 10 percent moisture and 20 percent protein has 27.7 percent protein on a DMB basis.
- With wet foods that have 75 percent moisture (leaving 25 percent that ISN’T moisture), to calculate DMB, divide the amount of listed protein – let’s say it’s 10 percent – by .25 to get 40 percent protein on a DMB basis.
See what happens? At first glance, you’d see the dry food label showing 20 percent protein and canned label showing 10 percent protein and assume the dry food has more protein. But once calculated on an apples-to-apples DMB basis, it’s clear that the amount of protein in the canned food is higher.
By the way, this tells us nothing about the quality or availability of protein, but that’s another story for another day.