Taking the Mystery Out of Dog Food Labels: “As Fed” Vs. “Dry Matter Basis”

How to Understand Dog Food Labels

Over the past week or so I have been working on adding to the low phosphorous dog food database.

Specifically, I have been adding new foods, updating discontinued foods, and adding sodium values where I can.

The foods in this database are dog foods for dogs with kidney concerns, dog foods for dogs with heart disease, dog foods for dogs with kidney stones and so on.

The database is designed to help you to find a food based on your vet’s recommendations for your dog’s unique needs, specifically phosphorus and sodium restrictions. It also includes a range of other important data, such as price!

The whole project was conceived after Jet developed struvite crystals in his urine and required a food with low phosphorus levels. Our vet at the time could only recommend Science Diet formula to us. After scanning the ingredient label, I shook my head and told them that I would find another solution and that is just what I did.

A special dietary requirement does NOT always mean having to go on a veterinary prescription diet or veterinary sold brand of food like Science Diet. Of course, in some instances, this WILL be the best option for a dog (which is why you have to work WITH your vet when choosing your dog’s diet.)

At the time of Jet’s urinalysis concerns, we went with California Natural Kangaroo and Red Lentil formula.


California Natural Kangaroo

If you are like me and you take researching dog foods into your own hands, it’s important that you actually know what you are looking at.

No, you aren’t expected to have a veterinary or nutrition degree, but you are expected to understand how to read the nutrients in a bag of dog food.

So, today, we are going to begin a series of articles designed to help you to get a better understanding of dog food nutrition labels.

This will not only help you to choose a dog food for your dog’s unique nutritional needs, but it will also help you to find multiple foods that will work for your dog.

Why would you want to find multiple dog foods that work for your dog? Well, you wouldn’t want to eat the same thing every day for the rest of your life, would you? Not only that but switching protein sources (when possible) helps to provide well-rounded nutrition AND helps to reduce the chance of developing food sensitivities.

So, let’s get to it!


    How to Understand Dog Food Labels


What Does ‘As Fed Basis’ Mean On Dog Food Labels?

Dog food contains moisture. When you look at the “as fed” nutritional data on your dog food label, the information you are looking at includes that moisture.

Think, for example of the grass, that a cow eats. If a cow eats 10lbs of grass, that 10lbs includes both the grass and the moisture that is contained in that grass.


What Does ‘Dry Matter Basis’ Mean On Dog Food Labels?

Now, if you look at the ‘dry matter basis’ nutritional information, this information takes out the moisture content.

Think, again of the grass, that a cow eats, but this time that grass has been pressed firmly to remove all moisture. This leaves you with only the grass or “dry matter”.

The same thing can be done to dog food…but why is it done?


Question Mark


Why Does Moisture Content Matter in Nutritional Profiles?

The average level of moisture in kibble is low, around 10% on average.

The problem is, that different food varieties contain different percentages of moisture.

Why is this a problem?

Because if you are comparing two varieties (or even two different types) of dog food, you have to be able to compare them using the same common denominator.

(Yes, I did just reference fractions…and you thought you’d never need to use fractions again!)




Finding a Common Denominator For Dog Food Nutritional Information

You can’t take a kibble with a 20% moisture level and a kibble with a 5% moisture level and compare the “as fed” nutrients in the same measure of both. It’s like comparing apples and oranges.

So, we need to find our “common denominator” by calculating our dry matter basis and reducing both kibble options to their dry matter components.

Let’s look at an example to see how it’s done…

You have just rescued a dog that is severely overweight. A 40lb dachshund.

Now, in addition to an exercise routine, your vet has recommended a low-calorie and a low-fat diet to get your dog down to a healthy 20lbs.

He recommends the following approach:

Calories: 496 calories a day until your dog reaches 30lbs and then a progress visit to reassess your dog’s weight loss plan.

Food fat content: A dog food with a fat content between 12 to 16%.

So, you go home and start your research.


Overweight Dogs


You want to do your research at home because there’s a lot of numbers, a few calculations, and a lot of companies (as I have recently found out) don’t provide you with all of the information you might need for your dog’s health (for example if your overweight dachshund also has heart disease and needs a low sodium food you may have to write or call a company to get this information.)

So, you start with a few brands of dog food that you like and start looking at the numbers.

You finally narrow your choices down to two different kibble options – Now! Sensitivity and Shine Adult Duck Formula and Pro Plan Focus Weight Management Dog Food.

So, now you need to compare the two.

We start by looking at the “As Fed” numbers for both foods…


Now! Sensitivity and Shine Adult Duck Formula Pro Plan Focus Weight Management Dog Food
Moisture Content: 8% Moisture Content: 12%
Calories: 438 kcal / cup Calories: 362 kcal / cup
Fat Content: 12% Fat Content: 12%


So from looking at the basic numbers we can see that the lowest calorie content is in the Pro Plan Focus Weight Management formula. But is this really the best choice?

To do this, we need to take the moisture out of the equation so that we can compare dry matter ingredients. So, we do the “dry matter” calculations.

To begin, we take the “as fed” moisture content and subtract it from 100. This gives us the percent of dry matter in the food.

We then take the “as fed” nutrient we want to compare, for example, calories, and divide that number by the dry matter content of the food that we just came up with.

So for example, our calories in Now! Sensitivity and Shine Adult Duck Formula is 438, and our moisture content is 8%. So we will take 438 / 92, which gives us 4.8666.

We then take that number and multiply by 100.

This gives us the calorie content of this food on a dry matter basis.

We use this same formula for any nutrient in the food when converting it from “as fed” to “dry matter” basis.

By converting the nutrients we are interested in comparing for your overweight dachshund to their dry matter basis, we can compare the two food varieties using a common denominator.

How is “dry matter” a common denominator?

Imagine you take a cup of the Now! formula and a cup of the Pro Plan Focus formula you want to compare. You separate the moisture content so that it is at the top of the measuring cup.

Now you can see that you have different levels of dry ingredients at the bottom of each cup of kibble and you have different levels of moisture content at the top of each cup.

Imagine taking out that moisture content from your kibble options so that you are only looking at the remaining dry matter from each cup of food. Your cup that had the highest moisture content is going to have less dry matter than your cup that had a lower moisture content.

This dry matter is what you are comparing in terms of nutrient content – 92% dry matter for the Now! formula and 88% dry formula for the Pro Plan Focus formula.

Now we want to convert all of the nutrients we are interested in for each of the kibbe options we are looking at so that we can properly compare them.


Now! Sensitivity and Shine Adult Duck Formula Pro Plan Focus Weight Management Dog Food
Moisture Content: 0 Moisture Content: 0
Calories: 438 / 92 = 4.8666 x 100 = 486.66 Calories: 362/ 88 = 4.1136 x 100 = 411.36
Fat Content: 12 / 92 = .1304 x 100 = 13.04% Fat Content: 12 / 88 =  .1363 x 100 = 13.63%


So, when we look at the numbers, it turns out that the calorie content of the Now! brand food is still higher than the Pro Plan food, but now there is a change in fat percentages when looking at dry matter.

Granted, in this case, the fat percentages differ by only a small amount, but in some cases, it differs by much more.

When we look at these two kibble options, we need to consider which would be more beneficial for your overweight dog. We can feed less kibble to make sure that your overweight dog isn’t eating too many calories, but we can’t take fat out of the kibble. So, in this instance, it may be a better option to go with the kibble option with the lower fat content and choose to feed less. This also makes more sense for your budget if the two kibble options are comparable in price since a single bag of food is going to last longer.


Wellness Wet Food


Comparing nutrients using a dry matter basis isn’t always necessary for kibble because most kibble options tend to have similar moisture levels. Where dry matter comparison truly comes into play is when you are comparing two different types of food – for example, dry food versus wet food, dry food versus dehydrated food, wet food versus raw food, and so on.

Want to learn more about the nutrition label on your dog’s food? Tomorrow we’re going to talk about percentages and milligrams! But for now, I’ve kept you long enough!

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