Comparing Dog Foods

About Comparing Dog Foods

Comparing dog foods is no easy task. The labeling can be hard to decipher, and many of us are left wondering which brand is really the most nutritious. When you also throw in the choice of whether to feed dry or canned food, the waters get even muddier.

Let's take a look at who sets dog food standards and the best way to compare nutrition.

AAFCO and Pet Food Nutrition

The Association of American Feed Control Officers (AAFCO) is the regulatory body that sets the standards for the nutritional content of dog food and other animal feeds. By law, all pet foods must meet AAFCO's minimum requirements to be labeled 100% nutritionally complete. However, just because a pet food meets AAFCO's minimum requirements still doesn't guarantee that all dog foods are of equal quality.

Quality and Digestibility

Let's talk about digestibility. Two dry dog foods may actually contain 18% minimum protein; however, the source of that protein determines how digestible it is. Real meat and less expensive meat by-products both have protein contents. Real meat is easier to digest, and therefore your dog is able to absorb more of the nutrients as the food passes through his system.

Greater absorption of nutrients equals fewer stools because more of the food has been completely digested. The question of digestibility also pertains to the rest of the ingredients in your pet's food. If your dog can't pull the nutrients from them, what good are they?

So why don't all dog foods use the most digestible, high quality ingredients? Because using lesser quality ingredients that still allow the food to meet AAFCO standards increases the manufacturer's profit margin.

Dry Kibble vs. Canned Dog Food

The rule of thumb for dog food is this: The higher the water content, the lower the concentration of nutrients; the lower the concentration of the nutrients, the larger the required serving size to attain the recommended amount of nutrition.

Canned dog food usually has higher water content than dry kibble; you then have to serve your dog a larger serving of canned dog food to obtain the same amount of nutrients as contained in a smaller serving of dry kibble. That's not necessarily a bad thing, as long as you understand the difference. Both forms of food can benefit your pet, and it's never a good idea to feed a single brand or type of food exclusively.

That said, water content alone cannot tell you if one food brand is higher in actual nutritional content than another. For that we need to look at the guaranteed analysis and learn to decipher its true meaning.

Understanding the Guaranteed Analysis

We've all looked at the guaranteed analysis table printed on every package of dog food. It's easy to come to the conclusion that comparing one dog food label to the next shows which food contains a higher percentage of nutrients, but in reality the analysis doesn't tell the entire story. To get a true comparison, we have to level the playing field by taking the water content out of the picture, and only look at what is left.

AAFCO actually bases their requirements for 100% nutritionally complete dog food strictly on the "dry matter" content. However, the analysis tables on nearly all dog food labels have been converted to reflect each package's feeding recommendations. This analysis can be a bit confusing, since the amount of food you need to feed in order to get the guaranteed results varies from brand to brand. If we want to make a truly informed comparison, we need to view these percentages the same way AAFCO does, by dry matter content.

Conversion Formula for Comparing Nutrient Contents

Here is a formula to help you convert the guaranteed analysis table into a dry matter profile for easier comparison.

Begin at 100%, and subtract the percentage of moisture listed on the label. The remaining percentage gives us the actual amount of dry matter in the food product. Next, we take the listed percentage of one of the main nutrients, and divide that number by the percentage of dry matter. This will give us the actual dry matter percentage of each nutrient in the food.

For example, let's say the water content of a particular brand of canned dog food is listed as 75%, and the crude protein content analysis is guaranteed to be a minimum of 6%. Subtracting the 75% water content from the 100% total product leaves us with 25% dry matter. Now, divide that 6% protein by the 25% dry matter and we get a dry matter protein content of 24%.

Now a bag of dry dog food carries considerably less moisture. Using the same formula, a product containing 6% moisture leaves a dry matter content of 94%. If the crude minimum protein analysis is 18%, that rounds out to a dry matter protein content of 20%. In this instance, the dry food contains lower protein content than the canned, but the results will vary as the percentages change from brand to brand.

Now that you know the formula, you can convert the other crude nutrient percentages listed in any guaranteed analysis table into a number that can truly be compared from one dog food to the next.