Why You Can’t Rely on the Guaranteed Analysis of Pet Food

Pet owners, veterinarians and retailers often rely on the guaranteed analysis (GA) of pet foods to help determine if the food provides adequate nutrition and to assess quality. Is this a good way to evaluate foods? The GA provides percentages – but does it tell us anything about the grams of protein, fat or other amount of other nutrients like calcium?

The short answer is no. The long answer is more concerning because the percentages listed on the GA are listed in terms of minimums and maximum which really just means that the GA provides an estimate of 4 main nutrients – protein, fat, moisture and crude fiber (not total fiber) which is misleading at best. It doesn’t even tell you the amount of animal or plant-based protein. In fact, a carefully crafted GA can make some of the worst pet foods look better than they are and be used as a tool to charge a high price tag despite low quality. Some GA’s will provide more information, but those values are usually optional and equally deceptive.

So how are pet owners and others supposed to evaluate pet food if the GA doesn’t provide the whole picture? The answer is: as a consumer or pet food retailer you have to ask questions.

What does the Guaranteed Analysis Provide?

We’ve established that the GA doesn’t tell you anything about the actual content of the food, but why is that? For example, looking at the GA of ‘Kibble A’ stating 24% protein and ‘Canned Food B’ stating 8.5% protein (table 1) – which food has a higher protein per serving? If you take the time to either do the nutrition math or contact the company for answers you’ll find that kibble A has 6.64 grams of protein per 100 calories and Canned Food B has 6.78 grams of protein per 100 calories (table 2).

Are you surprised to learn that the wet food has higher protein despite the large difference in percentage in protein? So are most pet owners, retailers and even some veterinarians. This is why advice to feed foods under or over a certain fat and protein percentage is severely flawed. It becomes even more problematic if you contact the company only to determine that they are unable to provide you with a full nutrient analysis of their food which would more accurately describe protein, fat and carbohydrate levels, but also vitamins and minerals.

Guaranteed Anylasis Comparison:
Guaranteed Analysis Kibble A Canned Food B
Crude Protein % 24% Min. 8.5% Min.
Crude Fat % 14% Min. 5.5% Min.
Crude Fiber % 5% Max. 1.5% Max.
Moisture % 10% Max. 78% Max.
Calories/Cup 378 451

Table 1

Nutrients in Grams

(per 100 calories)

Kibble A Canned Food B
Crude Protein 6.62 grams 6.78 grams
Crude Fat 3.86 grams 4.39 grams
Crude Fiber 1.38 grams 1.2 grams

Table 2

Looking at these tables you’ll see that even though the canned food has a lower percentage of protein and fat, it is higher in grams of protein and fat per 100/calories.

For crude fiber, this is percentage is not representative of the total fiber within the diet. In fact, this is a small portion of the total dietary fiber. Don’t believe me? A 2019 FDA report shows that Total Dietary Fiber (TDF) can be as much as 3-4 times higher than the crude fiber listed on the GA. So is crude fiber on the GA misleading? You bet!

What about the minimums (min.) and maximums (max.) listed on food labels?

Even more confusing is that you’ll often see ‘min’ or ‘max’ following protein, fat, fiber or moisture – meaning that the value could be higher or lower than the number you actually see. This number could actually vary quite a bit, which also means that the calorie content of said food could also vary widely from what is listed on the label. This also means that our example above is also a guestimate – at best. This is why asking for the ‘typical nutrient analysis’ is so important!


Understanding Moisture’s Role in Pet Food

To put this into context, you may have heard that protein should be below a certain percent value for growing puppies, for pets with kidney disease or for some dogs with behavioral issues. Or, you may have been told to find a food with a low percentage of fat for pets with pancreatitis or liver disease. The fact is that the percentage of protein or fat tells you nothing about the actual grams of protein that is within the food.

Remember when I said that a canned food with 8.5% protein can have more protein than a dry food with 24%? This is simply because the water content makes canned foods appear lower in protein, fat or other nutrients because water makes up a greater proportion of the food. Canned foods can be comprised of 70-80% moisture where dry foods typically sit around 10%. Said differently, if you adjust the moisture level of any pet food you can shift the percentages of protein, fat and fiber significantly while the grams of those nutrients stay the same.


A Bit About Protein

The percentage of protein or the grams of protein still does not tell you if the protein is able to be used by your pet. There are two distinct types of protein: plant, and animal. Proteins are made up of amino acids, think of these as building blocks. Amino acids are used for countless processes within the body and are necessary for life. They can be broken down into two main categories: essential and non-essential.

The body is able to make non-essential amino acids itself, but it MUST obtain essential amino acids from the diet. Plant-based foods typically lack or have inadequate levels of essential amino acids and therefore simply replacing animal protein with plant-based protein is not an even trade. Given the cost of animal protein, pet food companies will commonly formulate foods with higher plant-based levels of protein and supplement essential amino acids either with complementary animal sources or with the addition of a supplement.

This is one of the reasons why poorly formulated plant-based diets (especially with a lack of testing) for cats and dogs could be so detrimental. Therefore, if a pet food doesn’t have adequate levels of essential amino acids then it can lead to deficiencies and serious health problems. Additionally, some non-essential amino acids may become conditionally-essential in the case of certain diseases – an example would be taurine in dilated cardiomyopathy (DCM).

Label Update

What the above example shows is that the nutrition label is in need of a serious update. We now see that the GA based on percentages is a flawed model leading to a lot of misconceptions which are arguably detrimental to the pet. The GA also allows pet food companies to engage in deceptive marketing practices. A better option would be to present nutrition information in grams and milligrams for easy comparison – similar to the format of Table 2. Better yet, if companies made a full nutrition analysis (such as amino acids, fatty acids, vitamins and minerals) of their food readily available (e.g. on the company website) for consumers and veterinarians then the public would be better able to make educated decisions for their pet’s needs.

Owners, veterinarians and retailers need to ask all manufacturers for detailed information regarding the nutrient content of their formulas as well as the digestibility of the nutrients contained within it. Without evaluating these two factors there is no true way to know what the quality of the food is, regardless of how pretty the packaging is, how good the claims sound or what the company tells you. Proprietary is not an excuse for not providing these numbers either since anyone can send out a food for nutrient analysis and digestibility testing.

While these conversations take time for all parties, they are necessary in order to improve the pet industry. Pets are ultimately paying the price of untested pet food we we’ve seen in the Hill’s Vitamin D recalls, aflatoxin recalls and the DCM scare. The point is that if companies were doing their due diligence, testing these foods appropriately, each of these incidents could have been prevented.


In summary, the GA only provides scant information at best, as it supplies the estimated percentage (proportion of the food) of protein, fat, moisture and insoluble fiber. And as we learned above – it does not quantify the grams of protein, fat or carbohydrates in the food – or provide insight into the levels of vitamins or minerals. Pet food companies should be conducting full nutrient analysis of all of their formulas in order to ensure their food meets minimum nutrient requirements for the pet, but also to provide you with detailed to nutritional information so that you can make educated decisions based on your pet’s individual needs. 

About the Author: Nicole Cammack

Nicole is the founder & owner of award winning NorthPoint Pets & Company, in Connecticut. She is also the Founder & CEO of Undogmatic Inc. Her undergraduate and graduate education includes biology, chemistry, business and nutrition. She has worked in the pharmaceutical industry on multiple R&D projects and has had the privilege to learn from leading international figures in the human and pet health industry. She regularly lectures at national conferences, including federal, state, and municipal K9 events. Her current research involves identifying pathogenic risk factors and transmission among raw fed pets through a comprehensive worldwide survey.