Guaranted Analysis of Dog Food

The guaranteed analysis of dog food indicates the nutritional content of a given product. It is part of the mandatory labeling of dog food and must include at least the minimum fat and protein content and the maximum fiber and moisture content.

Many owners use analytical values while chosing a dog food. But how are the values calculated? And what do the guaranteed amounts of nutrients tell us about a dog food product?

What is a Guaranteed Analysis?

The guaranteed analysis is part of the mandatory information on every dog food label.

This information is intended to ensure a consistent nutrient profile and allow comparison of different products.

These are the nutrients reported in the guaranteed analysis according to the AAFCO guidelines:

  • Crude Protein (min.)
  • Crude Fat (min.)
  • Crude Fiber (max.)
  • Moisture (max.)

They are expressed as a percentage by weight of fresh matter.

Guaranteed values for other nutrients may become mandatory to support claims made in labeling such as “high in calcium”.

By the way, the term “crude” is just how these results are reported. It has nothing to do with the quality of nutrients or ingredients!

While dog foods in the USA must specify the amount of crude fiber, this information is missing in foods sold in the EU. Instead, EU manufacturers are required to specify how much crude ash is found in their products.

Ultimately, consumers need all values to estimate the carbohydrate content of a food. And it almost seems a bit intentional that in both cases just one random value is withheld.

What To Expect from the Guaranteed Analysis

To figure out how much of each nutrient is in dog food, scientists test a bunch of samples in a lab. Basically, they break down the food and look at its different parts to see what it’s made of.

They use the same methods for every type of food, brand, and batch to make sure the results are fair and comparable.

For example, they can tell how much protein is in the food by looking at how much nitrogen it has. And they figure out the crude fiber content by first removing all the soluble stuff.

But these values do not exactly represent the actual amount of each nutrient. The testing methods used are known to over- or underestimate the nutrient contents of food.

For example, a study that reviewed the manufacturer’s claims in dog foods purchased in Slovakia concluded that most of the analyzed foods contained less fat and more fiber than claimed[2].

In the end, the values of the guaranteed analysis only provides very rough estimates and can differ significantly from the actual composition of a dog food.

The guaranteed analysis tells you whether a dog food meets the minimum standards. It also gives you some idea about the general composition of a product.

In general, don’t try to read too much into the analysis label.

The guaranteed analysis does not specify the actual amount of protein, fat, water, and fiber in the product. It only gives the minimum or maximum for each value.

The values on the dog food label do not have to be perfectly accurate anyway. There are margins of error taking into account technical inaccuracies and natural variations in ingredients.

Crude Protein

The most common method to measure crude protein involves breaking down the protein and measuring how much nitrogen gets released.

Since protein contains about 16% nitrogen by weight, the amount of protein can then be extrapolated retrospectively.

It’s important to note that this is not an exact measurement of the actual protein content of the dog food.

By design, crude protein includes all nitrogen-containing compounds, e.g. plant alkaloids.

However, it is a useful tool for comparing the relative protein content of different products.

Many people even check a dog food’s protein content before even looking at the ingredient list.

But analytical values can’t tell you anything about protein quality or bioavailability.

A high protein content doesn’t mean the food is rich in meat!

Average dry foods report 18-40% while wet foods about 4-15% of crude protein. To compare food types, you should know how to calculate protein content on a dry matter basis.

Dogs can thrive on diets with very different protein levels as long as their basic needs are met. Protein provides your dog with amino acids, any surplus is converted into glucose or excreted.

Since protein is one of the more expensive ingredients in dog food recipes, some manufacturers try to use as little as possible.

On the other hand, foods with super much protein are not always high-quality products. And the analytical protein-content can be boosted with low-quality ingredients.

We recommend checking the overall product composition and quality than obsessing over protein content.

And please take note that in some conditions like renal disease, soometimes a low-protein food can be beneficial.

Crude Fat

Crude fat is measured by solvent extraction, which involves treating the food sample with fat solvents such as ether or hexane.

The amount of fat reported on the dog food label represents the total amount of fats, oils, and waxes in the dog food, including both essential fatty acids and non-essential fats.

Fats in dog food provide energy and essential fatty acids. They also act as flavor enhancers and many dry foods are spray-coated.

The recommended levels of crude fat in dog food can vary depending on your dog’s age, breed, or activity level.

In general, adult dogs require a minimum of 5% to 8% fat in their diet, while puppies and pregnant or lactating dogs may require higher levels to support their increased nutritional needs.

The maximum recommended level of crude fat in dog food can also vary based on individual needs, e.g. in working dogs. In general, fat content should not exceed 20-30%.

Diets that are excessively high in fat can contribute to obesity, pancreatitis, and other health problems in dogs.

Crude Fiber

When measuring crude fiber the food sample is boiled in acid and alkali solutions to break down the protein, fat, and other nutrients.

This leaves only the fiber portions that are not digestible and will pass your dog’s digestive tract unchanged.

Crude fiber should not be confused with prebiotics!

Much of the actual dietary fiber present in dog food is fermentable by the dog’s intestinal flora and contributes to nutrition.

There is no dietary need for fiber in a dog’s diet. Nevertheless, most diets contain about 2-15%.

That’s because fiber promotes healthy digestion or helps regulate blood sugar levels.

Many weight management formulas are rich in fiber.

They often contain cellulose as a bulking agent to make your dog feel full without adding more energy to his diet.

However, excessive levels of fiber in your dog’s daily diet can interfere with the absorption of other nutrients and can lead to digestive upset.

Crude Ash

The method to quantify levels of inorganic matter involves burning the dog food sample at a high temperature to completely incinerate all the organic matter.

This leaves all the inorganic mineral components such as calcium, phosphorus, magnesium, and potassium.

Crude ash represents a dog food’s mineral content.

the term does not refer to actual ash, but rather the inorganic mineral components left behind after incineration

The recommended levels of crude ash in dog food can vary depending on the dog’s individual needs and health status. In general, the maximum recommended level is around 8% to 10% for dry food.

Manufacturers usually choose not to include crude ash on their labels because they don’t have to and the term ash might confuse their customers.

However, this value could provide useful information about the overall quality of the dog food ingredients.

Moisture

The moisture content determines whether a food is dry, semi-moist or wet.

In general, kibble has a moisture content of around 10-12%, while wet dog food has a moisture content of 75-85%.

Moisture content in dog food is typically measured by drying a sample of food until all the moisture is removed.

The amount of water lost in dry matter is then used to calculate the initial moisture content of the dog food.

It’s important to note that the moisture content can affect the nutrient composition of dog food.

Dry dog food typically has a higher concentration of nutrients compared to more diluted wet dog food.

The high moisture content in wet dog food, however, can help maintain hydration and urinary tract health in dogs.

It’s also important to choose a dog food with an appropriate moisture content based on your dog’s individual needs and preferences.

For example, some dogs may prefer the taste and texture of wet or dry dog food. Consulting with a veterinarian can help determine the best type of dog food for your dog.

Typical Analysis

Some manufacturers voluntarily give a typical analysis of their products. These values often provide more detailed information.

But they are often obtained from both actual lab analyses and calculated values. Sometimes these values deviate greatly from the guaranteed value because they try to report the actual amount of nutrients instead of a minimum and maximum.

Whenever possible, the manufacturer’s average nutrient profile should be used to evaluate a dog food!

Further Reading

[1] Beynen. 2014. Petfood label: analysis panel.

[2] Rolinec et al. The nutritive value of selected commercial dry dog foods. Acta fytotechnica et zootechnica. 2016. 10.15414/afz.2016.19.01.25-28.