How to Compare Canned Dog Food

You want to feed your dog canned food, but you're not quite sure how to compare the foods. All dog food percentages are calculated on a by-weight basis, meaning the percentages include water, ash content, fiber and carbohydrates instead of comparing food according to its actual energy percentage levels. To understand how much protein and fat you're feeding your dog, you have to compare dry-matter percentage. Or, if you're wondering about the energy percentage, compare caloric percentages.

Instructions

1

Compare the labels and make certain the food is certified by the Association of Animal Feed Control Officials, which has guidelines for dog food. The food needs to be complete and balanced. The label should state that it is approved for All Life Stages, Growth (meaning puppies) or Maintenance (meaning adults).

2

Look at the ingredient label. The first ingredient is likely to be water, but the next several ingredients should be the protein and fat sources. Look for high-quality protein sources, such as meat (poultry, beef, lamb), and by-products.

3

Write down the percentages on the guaranteed analysis label. You should have something that looks like this: Crude protein, min 9%; Crude fat, min 6%; Crude fiber, max 1%; and Moisture, max 78%. Although not listed, ash is about 6 percent of dry matter. Fiber is considered a carbohydrate and isn't counted in the equation.

4

Subtract the moisture from 100 to get your dry-matter percentage. In this case, 100 - 78 = 22 percent dry matter.

5

Divide the protein and fat by the percentage of dry matter. This will calculate the percentage of nutrients in dry matter. So 9 / 22 = .409 x 100 or 41 percent protein and 6 / 22 = .272 x 100 or 27 percent fat.

6

Calculate the amount of carbohydrates: 41 percent protein + 27 percent fat + 6 percent ash = 74 percent. Subtract 74 from 100; the food is 26 percent carbohydrates.

7

Calculate the energy percentages. Protein and carbohydrates have 4 kilocalories per gram and fat has 9 kilocalories per gram. Energy from protein is 41 g/100 g x 4 kcal/g = 164 kcal/100 g; fat is 27 g/100 g x 9 kcal/g = 243 kcal/100 g; and carbohydrates is 26 g/100 g x 4 kcal/g = 104 kcal/100 g.

8

Make calculations for another can of food and compare the energy values.