Guaranteed Analysis

/Guaranteed Analysis
Guaranteed Analysis 2016-12-16T21:42:48+00:00

The AAFCO (Association of American Feed Control Officials) regulations state that guaranteed analysis is required to be on the pet food label.

Guaranteed analysis determines minimum percentages of crude protein and crude fat, and maximum percentages of crude fiber and moisture.


The word “crude” refers to the exact method of testing the product, not to the quality of the nutrient itself.

The principle of the Guaranteed Analysis section in dog food labels is to make it easy for clients to compare four significant nutrients.

Though, when this information is used alone can be ambiguous. The system used for reporting the percentages does not succeeds to consider the widely varying quantity of water contained in different types of dog foods. For example, this can be a decisive factor when comparing moist foods, like canned foods, with dry kibbles.

AAFCO regulations

According to AAFCO regulations, the guaranteed analysis is just required to list four nutrients:

  • Crude protein
  • Crude fat
  • Crude fiber
  • Moisture (water)

Still, numerous dog food companies adjoin additional guarantees to provide you with more information about the food and as a mark of quality.

Crude protein is a measurement of the guaranteed minimum level of protein in the food.

By AAFCO regulations, a food that affirms a guarantee of 21% protein, may have no less than 20.4% protein. There is not a specific maximum level, but the protein is typically within 2% of the target.

My advice:

After you check the level of protein, you should look at the ingredient listing to see where that protein is coming from.

Crude fat measure is a minimum guarantee, with a 10% permissible variation. So, if the guaranteed minimum fat content is 15%, the minimum allowed by AAFCO would be 13.5%.

Crude fiber value is typically low and is a maximum level.  In hairball foods and weight loss diets, you will frequently see a higher level of fiber, usually 6-8%. Higher fiber formulas will result in larger stools.

AAFCO recomendations

Nutrients Percentages
Protein 18 – 22.5% (minimum)
Fat 5.5 – 8.5 % (minimum)
Fiber 4 % (maximum)

What is the meaning of…?

Crude Protein?

The “crude protein” refers to an approximation of the total quantity of protein in the dog food.

Protein is the most costly ingredient in dog foods. Dog owners may consider that the terms “crude protein” and the number with a “%” sign next to it refers to the amount of animal protein there is in the food. Instead, “crude protein” is in fact a chemical analysis of the food whereby the amount of nitrogen present is used to estimate the quantity of protein in the food.

Nitrogen comes from animal protein, but it also comes from non-animal proteins like grains, plus other non-protein nitrogen sources.


This fact clearly creates a gap between what you think you are buying and feeding your dog and what has really been used to determine crude protein percentage.

The crude protein percentage reflects the quantity of all protein, regardless of its source. It doesn’t indicate protein’s:

  • Type
  • Quality
  • Digestibility

Thus the dog food could enclose bad ingredients as a source of protein like chicken feet or soy.

Crude Fat?

Dogs require fat to help in the absorption, storage and transport of fat-soluble vitamins and as a source of vital fatty acids.

Crude fat is an estimation of the amount of fat before dog metabolizes his food. But just like crude protein value, crude fat may include good quality sources like fish oil or low quality such as mineral oil.

Crude Fiber?

Fiber helps gastrointestinal health and is the not poisonous parts of plants or similar carbohydrates that resist digestion and absorption in the small intestine and ferment in the large intestine. Crude fiber reflects the fiber content of the dog food. You don’t want to buy a diet with too much fiber because your dog can not digest it. Once again the quality of the fiber source is not evaluated by this parameter.


Diets vary significantly in the amount of moisture they contain. The relative moisture content for canned food is 75-78 %, whereas dry food holds only 10-12 % of water.

If you compare the guaranteed analyses of dry and canned foods you will find that the content of crude protein and other nutrients are inferior for the canned product because these nutrients are diluted in a larger quantity of water.

Guaranteed analysis is not helpful in comparing foods. However, if you use these data to compare foods you must convert the given information to a dry matter basis. Doing this conversion you get rid of moisture variability.

I believe that:

Breed, activity level, metabolism, season and genetics all play a important role in determining which diet is best for an individual dog.

Regarding two main ingredients – protein and fat – commonly the references for dogs are:

Protein (percentages are all on a dry matter basis)

Lyfe Stage Percentages
Adult dogs 15-28%
Puppies and pregnant/nursing dogs 28-35%
Old  dog 15-20%


Fat (percentages are all on a dry matter basis)

Lyfe Stage Percentages
Adult and old dogs 5-20 %
Puppies and pregnant/nursing dogs 30 %
Obese animals 5-15 %


You can consult our Dog Food Selector  and read our dog food reviews which include the information about the quality of ingredients and guaranteed analysis on a dry matter basis for each diet analyzed.

Why was the Dog Food Selector created?

Each dog has unique needs... The approach "one food for all dogs" isn't the more suitable. Dogs have different sizes, different life stages, unique breed characteristics, health conditions and a few other factors... Choosing the right food for your dog may help him or her life a longer and healthier life! We exist to make that task easier for you.

How does the Dog Food Selector work?

It's quite simple... It's a 1-2 step process. You just have to fill in the form with your dog's characteristics, like gender, age, size, activity, health conditions and a few other important data and click "search". Then, you'll see a list of dog foods with the highest review score. If you wish you can see all the detailed review of each individual dog food.