The most difficult challenge of choosing dog food is deciphering the label. Although not perfect, the human food nutrition labels are much easier to understand than dog food labels. It is very difficult for dog owners to really find out the nutritional content of their dog food. This is the first in a series to hopefully shed some light on dog food labels.
The Guaranteed Analysis
The guaranteed analysis is the most basic nutritional information required for dog food packages. The regulations require that the manufacturer state the percentage of crude protein, crude fat, crude fiber and moisture content of the food. The notation “crude” refers to easy, imprecise analytical tests on the food.
These values do not indicate how digestible or how much will actually be absorbed in the intestines. In other words it is a measure of quantity, not quality. In fact a well-known specialty diet company had a very successful advertising campaign poking fun at the “crude” designation. Their ad pointed out that a work boot and a quart of motor oil fulfilled the guaranteed analysis for dog food but indicated the digestibility problems, not to mention the obvious other problems.
Crude protein is always expressed as a minimum while fat, fiber and moisture are maximums. This means that the food can contain more protein or less fat, fiber and moisture. But the amount of difference does not have to be proven or disclosed.
But guaranteed analysis is all we have to work with. Below is a chart of comparing the guaranteed analysis of real brands of dry and wet dog foods.
|Guaranteed Analysis-Dry||Guaranteed Analysis-Wet|
Dog food manufactures are not required to list the carbohydrate content of their food. But it can be calculated from the guaranteed analysis. All foods contain only 6 basic things, protein, fat, fiber, moisture, ash and carbohydrates. Ash is what is left if you burn off the energy contained in the protein, fat, carbs, and fiber and evaporate the water. Basically, it is the minerals in food that don’t burn. Some companies list the ash content on the guaranteed analysis. If ash is not listed, 3% is a good estimate for most foods, wet or dry. With this information we can calculate the carbohydrate content of dog food. The equation is:
100% – %Protein – %Fat – %Fiber – %Moisture – 3% (ash) = %Carbohydrate
Using the equation and the guaranteed analysis of the dry food in the chart the carbohydrate content is:
100 – 21 -10 – 4.5 – 12 – 3 = 49.5% Carbohydrate
Dry food is generally high in carbohydrates. The reason is that it won’t “pop” in to the kibble shapes unless carbohydrates are the major ingredient. This is true even of the more expensive brands.
Canned food, on the other hand, generally has less carbohydrate. Let’s calculate the wet food in the chart.
100 – 8 – 3 – 1 – 82 – 3 = 4% Carbohydrate
By understanding the guaranteed analysis, you can compare the protein, fat and carbohydrate content of competing brands of food. This can help you choose the right food for your dog’s nutritional needs.
Watch for the next installment of “Understanding Dog Food Labels” where we use guaranteed analysis to compare the nutritional content of dry food to wet food.
~Dr Ken Tudor
THE DOG DIETITIAN