Some companies are now producing fairly healthy, grain-free, high-meat-protein, low-carbohydrate canned and raw food diets. However, many of these same companies also produce dry versions of their cat food and some of the canned varieties have ingredients including but not limited to: potatoes, vegetables, fruits, unsafe preservatives, and fish ingredients.
Remember, that from time to time, pet food companies change their ingredients. Please make sure to read the labels before purchasing and using all cat food products and to work in conjunction with your veterinarian. When choosing a food, look for Protein higher than 45% DMB, Fat 25 – 35% DMB, and less than 10% DMB Carbohydrates.
Many canned kitten formulas will meet these values. When choosing any formula, make sure to compare the quality of the ingredients. In almost all cases, a lower quality canned cat food with meat by-products is actually better than a “premium” carbohydrate laden dry food. However, the quantity of lower quality food may need to be increased in order to provide the same nutrition as a smaller quantity of higher quality food, thereby doubling its cost.
Digestibility
Digestibility refers to the extent to which an eaten nutrient is absorbed from the animal’s digestive tract and transported by the blood to the millions of cells in the body. The best way to determine the digestibility of the food is to measure the amount eaten, measure the amount passed from the body in the stool, and then compare the two.
Cats fed extremely cheap food made with low-quality grains and grain by-products will pass three or more stools per day. The actual volume of these stools might even be more than the amount of food eaten. This is because as indigestible food travels through the animal, it absorbs quite a bit of water which increases its bulk. The digestibility may only be about 70 – 85% in lower quality foods.
If an animal eats a food that is highly concentrated, say more than 90% digestible, it will still produce a stool but perhaps only once a day. The stool will be well formed and firm, however, it is composed of both undigested food and the residue of intestinal secretions and bacteria.
The digestibility of the food is an important consideration for cat owners. You are paying for the amount of food in the bag or can, not the amount the cat digests and absorbs. In addition, lower digestibility means more litter box cleanup. Choosing a food simply because it appears inexpensive does not mean that it is a good buy. Cost per feeding is the only way to determine the actual cost of the food.
Metabolizable Energy Content (MBE)
Metabolizable energy (total calorie content) is the most accurate way to compare foods with one another. This measurement disregards any part of the food that does not provide calories such as moisture, ash, or fiber. It only considers the fact that calories are derived from the protein, fat, and carbohydrate portion of the food.
Pet food companies currently list these values on some labels but they can usually be acquired from their website and may appear, for example, as 1,411 Kcal/kg.
However, an even better assessment would be the ME Profile (metabolizable energy profile) which would list calories from protein, fat, and carbohydrates individually for comparison.
Reading and Interpreting Pet Food Labels
Guaranteed Analysis (GA)
Guaranteed Analysis values are simply a range (minimums and maximums) of the levels of water, protein, fat, et. al. that are contained in the cat food. So, if the label states that there is a minimum of 6% fat, there could be 12% fat in the food as long as the quantity is 6% or higher. Ideally, the label should contain the more accurate As Fed (exact measurement) and Dry Matter Basis (removal of water) values or the percentage of calories (metabolizable energy profile).
As Fed Values (AF)
The exact or as fed values are the actual measurements of the ingredients in a sample of the food. These values more accurately reflect what is in the product (unlike the GA with minimums and maximums). Obviously, between different production runs of food, there will be variations, but these variations will be minimal. Some companies list these As Fed values on their websites, if not, you may request the value from the manufacturers. Like the GA, the AF values also include the water content of the food so it is impossible to directly compare canned food to dry food by comparing the numbers listed on the package label.
Dry Matter Basis (DMB or DM)
Dry Matter Basis removes the water from the equation. When foods are considered on a dry matter basis, they can be directly compared to one another. In other words, a canned food with 78% water can now be compared to a dry food that contains 11% water.
At first glance, it appears that the dry food below has more protein than the canned food. However, the canned food on a dry matter basis contains 45% protein as opposed to the dry food which contains 40% protein, when calculated.
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Dry Food
|
Canned Food
|
||
|
Protein |
36% |
Protein |
10% |
|
Fat |
18% |
Fat |
5% |
|
Moisture |
11% |
Moisture |
78% |
Calculating the DMB (Dry Matter Basis):
Dry Food Protein = 36%
Dry Food Moisture = 11%
100% (dry and wet) – 11% (wet) = 89% dry
(36% Protein / 89% dry) x 100 = 40% Protein DMB in dry food
Canned Food Protein = 10%
Canned Food Moisture = 78%
100% (dry and wet) – 78% (wet) = 22% dry
(10% Protein / 22% dry) x 100 = 45% Protein DMB in canned food
You can easily calculate the DM basis of any pet food using our Online Calculators.
Calculating Nutrient Percentages
Unfortunately, it is rare to see the carbohydrates listed for cat foods. If companies do offer this information, it is usually only found on their websites. This value, however, is just as important as the protein and fat content. There are three basic methods used to calculate the value of an individual nutrient using either the GA or AF values (always use the AF values when possible, as they are more accurate):
• As a percentage of food weight (includes water).
• As a percentage of dry matter weight (no water).
• As a percentage of calories (no water).
It is best to view the nutrient by the percentage of calories it provides, however, most manufacturers use the weight percentage instead. Although the Guaranteed Analysis values are not accurate (they can be found on the labels of all pet foods), they will give you an estimate of the percentages of the nutrients in the food. It is best to contact the manufacturer for the As Fed values for your calculations. These are sometimes posted on the companies’ websites.
Calculate the Percentage of Food Weight
To calculate the approximate weight of the carbohydrate in a food, add up the values for protein, fat, moisture, fiber, and ash and subtract this value from 100%.
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As Fed Values per 100 grams
|
|
|
Protein |
10% |
|
Fat |
5% |
|
Moisture |
78% |
|
Fiber |
1% |
|
Ash |
1.95% |
10 + 5 + 78 + 1 + 1.95 = 95.95%
100% – 95.95% = 4.05% Carbohydrate Weight
Calculate the Percentage of Dry Matter Weight
Dry Matter Basis removes the water from the equation.
Convert 4.05% Carbohydrate Weight to DMB
100% (dry and wet) – 78% (wet) = 22% dry
(4.05% Carbohydrate / 22% dry) x 100 = 18% Carbohydrate DMB
Calculate the Percentage of Calories
This is the best method for comparing values.
A cat should not receive more than 10% of their daily dietary calories from carbohydrates, less than 5% is best.
Protein and Carbohydrates contribute 4 calories per gram.
Fat contributes 9 calories per gram.
For conversion, you may use either the GA values or the AF values. Whichever method you choose to use for the calculations, make sure to remain consistent with all values. AF values are more accurate.
|
As Fed Values per 100 grams
|
|
|
Protein |
10% |
|
Fat |
5% |
|
Moisture |
78% |
|
Fiber |
1% |
|
Ash |
1.95% |
|
Carbohydrates
|
4.05%
|
10g Protein x 4 Calories = 40 calories Protein
5 g Fat x 9 Calories = 45 calories Fat
4.05 g Carbohydrate x 4 Calories = 16.2 calories Carbohydrates
40 calories Protein + 45 calories Fat + 16.2 calories Carbohydrates = 101.2 calories per 100 grams of food (≈3.5 ounces)
To calculate the percentage we must divide the calories for each nutrient by the total calories in 100 grams of food:
(40 calories of Protein / 101.2 calories) x 100 = 39.5% calories from Protein
(45 calories of Fat / 101.2 calories) x 100 = 44.5% calories from Fat
(16.2 calories of Carbohydrates / 101.2 calories) x 100 = 16% calories from Carbohydrates
Using these equations will help you to analyze and compare foods that are both processed differently (wet versus dry) and include differing amounts of nutrients (protein, fats, and carbohydrates). Calculating the dry matter basis or caloric content of the ingredients will help you make a better commercial food choice for your cat. Many commercial foods contain between 30-50% DMB carbohydrates. Providing your cat with a diet that is under 10% DMB carbohydrates daily caloric intake is a much better choice.
If at all possible, always acquire the As Fed values from the manufacturer and convert them to a dry matter basis so you may calculate the most accurate results.
Commercial Food Criteria
The following is a short list of requirements for a choosing a commercial cat food. If the commercial food in question meets the following criteria, then look for the quality of ingredients and question the company as to the source of those ingredients.
• Wet only diet – canned or raw
• Protein sources – chicken, turkey, rabbit, lamb, venison (beef & fish may be hyperallergenic and fish may contain high levels of heavy metals, pesticides, and toxins)
• Grain-free and soy-free
• High meat protein – > 45% DMB
• Moderate fat – 25-35% DMB
• Low carbohydrate – <10% DMB
Benefits of a Canned vs a Dry Diet
You may notice some of these changes immediately or it may take a few weeks to months for a positive outcome. It depends on the current health and physiology of your cat.
• Higher digestibility.
• Higher bioavailability.
• Less stool odor and better formed.
• Overweight cats will lose weight.
• Urine production will double due to proper hydration. Your cat will probably drink little to no water. However, keep fresh water available at all times.
• Dry, flaky skin and dull coat will disappear. Fur will become soft and glossy.
• Cats may become more energetic and playful.
• Some cats exhibit less shyness and exhibit more social interaction with other cats and people.
• Less vomiting and diarrhea . However, when a diet change is instituted, some cats may experience these symptoms for a week or two. Always proceed slowly when introducing new foods.
• Decrease of hairballs.
• BUN (blood urea nitrogen) a non-toxic by-product of protein metabolism, may be higher than the laboratories’ safe range limits due to the high-meat-protein content of the food.
• Cats with urinary problems may see a marked improvement which may lead to complete remission without recurrence.
• Cats with IBD may see a marked improvement.
• Cats with diabetes will see a marked improvement which may lead to complete remission without recurrence
Only change your diabetic cat's diet with the assistance of your veterinarian – as blood sugar decreases, the insulin dose will also need to be decreased or a deadly condition of hypoglycemia may occur, usually within 24 hours).
Information on this site is for general information purposes only and is provided without warranty or guarantee of any kind. This site is not intended to replace professional advice from your own veterinarian and nothing on this site is intended as a medical diagnosis or treatment. Any questions about your animal’s health or diet should be directed to your veterinarian.
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