Without a measuring method known as the "dry matter basis", it would be very difficult to compare dog food products.
Pet food companies report on the nutrient content of each product using what's known as the "Guaranteed Analysis." This Guaranteed Analysis is the equivalent of the Nutrition Facts panel that is printed on all human food products sold in the USA and Canada.
In pet food products, the Guaranteed Analysis is designed to allow consumers to compare the amounts of four (or more) critical nutrients:
However in practice, using these numbers as published in the Guaranteed Analysis can actually be quite misleading - especially when comparing wet and dry products.
According to the FDA:
“To make meaningful comparisons of nutrient levels between a canned and dry product, they should be expressed on the same moisture basis.”
The measuring method known as the "Dry Matter Basis" (or DMB) allows us to do that. To summarize, the DMB is a calculation method that removes the moisture content from a product and then reports the remaining nutrient values (protein, fat & fiber) based on the percentage of the remainder.
Removing the moisture content before evaluating products is especially important when comparing a wet food vs a dry one. Wet dry food typically consists of 80% moisture, while dry foods are approximately 10% moisture.
This can be most easily illustrated using 2 Wellness products: canned Wellness Core Whitefish, Salmon & Herring and dry Wellness Core Ocean.
| Nutrient | Wellness Core Whitefish, Salmon & Herring | Wellness Core Ocean |
|---|---|---|
| Protein | 10.0% | 34.0% |
| Fat | 6.0% | 17.0% |
| Fiber | 0.5% | 7.0% |
| Moisture | 78.0% | 10.0% |
| Ash | 0.0% | 3.6% |
Looking at the above chart, it appears the dry Wellness Core Ocean has over 3 times the protein of the canned Wellness Core Whitefish, Salmon & Herring! However, once the moisture is removed from the equation and the other nutrients are recalculated as a percentage of the remainder, we can see that this is not the case.
| Nutrient % | Wellness Core Whitefish, Salmon & Herring | Wellness Core Ocean | Calculation Formula |
|---|---|---|---|
| Dry Matter | 22.0% | 90.0% | 100 - % Moisture |
| % Dry Matter Protein | 45.5% | 37.8% | GA Protein / Dry Matter |
| % Dry Matter Fat | 27.3% | 17.8% | GA Fat / Dry Matter |
| % Dry Matter Fiber | 2.3% | 7.8% | GA Fiber / Dry Matter |
| % Dry Matter Ash | 0.0% | 3.9% | GA Ash / Dry Matter |
Using the above DMB chart above instead, we can see the wet Wellness Core Whitefish, Salmon & Herring product actually contains over 45% protein (for all non-moisture weight), compared to the less thna 38% that is in the dry Wellness Core Ocean product. Instead of only consisting of 1/3 of the protein of the dry food as the Guaranteed Analysis initially suggests, the wet food actually consists of 20% more! Without calculating the DMB values for the two products, it would be impossible to see this.
Fortunately, DogFoodDB has calculated the Dry Matter Basis values for each of our products reviewed, allowing you to easily compare and contrast without having to manipulate the numbers yourself!
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Note that this blog post was originally posted over at our sister site, CatFoodDB. The principles and calculations behind dry matter basis are identical for both cat and dog foods.
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