Lisa A. Pierson, DVM
Cat Food Ingredients
Composition of Cat Food
By-products in Cat Foods
Cost and Quality of Cat Foods
Calculating Protein/Fat/Carbohydrate Percentage of Cat Foods (This may give you a headache…..)
Contacting Pet Food Companies
Do Not Recommend
Raw Meat and Bones Diets – comments only/no list
Before you get too confused when reading this page, I will say at the outset: I would much rather see a cat eat any canned food versus any dry food – regardless of the price-point of the canned food. This includes Friskies, 9-Lives, Fancy Feast, etc.
Canned food is healthier than dry food because:
- All canned foods contain an appropriate (high) amount of water which is critical for urinary tract health. Please see Opie’s page – Feline Urinary Tract Health.
- The protein in canned food is more apt to be higher in animal-based protein versus plant-based protein – contrary to most dry foods. Keep in mind that we are feeding cats (strict carnivores) not cows.
- The carbohydrate level of most canned foods is lower than that of most dry foods.
There is no dry food that covers all of the very important points listed above. None – because all dry food is, well, dry (water-depleted).
If your cat is a dry food addict, please see Tips for Transitioning Dry Food Addicts to Canned Food.
Note: If you are tempted to write to me to ask about a particular food, please see Contacting Pet Food Companies below.
If you need more help past what is contained on this extensive website – including this page – see Consultation Service.
Specific advice regarding selecting a cat food will not be provided via email.
General comment: For healthy cats, pick canned foods that are below 10% calories from carbohydrates, at least 40% calories from protein, and approximately 50% fat calories or less.
- “Grain-free” does not necessarily mean “low-carb.” Many companies add in large amounts of potatoes or peas which are high in carbohydrates but are not “grains.”
- Grains and vegetables contribute to both the carbohydrate and protein content of food but understand that the protein from these ingredients is plant-based, not animal-based. As explained in my Feeding Your Cat: Know the Basics of Feline Nutrition, cats are strict carnivores and need to get their protein from other animals – not plants.
Therefore, when comparing two foods with the same percentage of protein, it is very important to note the quality (biological value) of the protein. Plant-based proteins are very low in quality/biological value.
- I often get asked for my opinion on dry foods that are relatively low in carbohydrates – e.g. – Young Again. The people who ask me this question have not read this website – including the Urinary Tract Health page – and have not taken a good long look at Opie’s pictures on that page. Otherwise, they would know just how strongly opposed I am to the feeding of dry food to cats – no matter what the ingredients are, or what the carbohydrate level is.
I wonder how many people would continue to condone the feeding of a water-depleted diet to cats if they had a cork inserted into their urethra and experiences the susequent excruciating pain that occurs when a urethra becomes obstructed. After experiencing the tremendous suffering that commonly occurs when cats are fed dry foods I would bet that their love affair with dry food would end very quickly.
Carbohydrates are not the only issue that we need to focus on when feeding cats. The water content of the food is also critical given the low thirst drive of the feline species.
Contrary to popular belief, cats do not drink enough water from a bowl to make up for the hydration deficit caused by feeding dry food. Studies have shown that when cats are fed water-rich diets (canned or homemade diets) that mimic their prey (~70% water), they rarely drink from a water bowl yet their intake of water is double what it is when dry food (5-10% water) is fed. This is taking into account the water from the food as well as from the water bowl.
If you do not want to read any further and want three quick bullet points, here they are:
- Get the dry food out of your cat’s diet.
- See the Cat Food Composition chart. Feed canned food with less than 10% of calories from carbohydrates. Next, look at the fat and protein. In general, aim for higher protein and lower fat.
- If you are caring for a diabetic cat that is on insulin please read Feline Diabetes – especially the STOP sign section – and make sure that you understand the highly probable need to decrease the insulin dosage if you are decreasing the carbohydrate intake of your cat.
When determining the quality of a pet food, there are two main factors involved:
- ingredients – what is in the food – with amount of each item an important issue but this information is not available on the label
- composition – the percentage of calories that come from protein, fat, and carbohydrate sources – also not on the label – see the Cat Food Composition chart
I realize that the “not on the label” comments are frustrating but welcome to the world of pet foods where the manufacturers are not required to put much usable information on their packaging – unlike the case with food targeted for humans.
Unless you are dealing with an allergy to a specific ingredient, the composition of a diet is generally more important than the ingredients as long as you pay attention to where the protein is coming from (i.e.- animals versus plants).
The composition of a feline diet is important because cats are designed to eat a high protein (~50% of calories, or more), moderate fat (~40% of calories or less), and very low carbohydrate (1-2% of calories) diet.
Unfortunately, this fact is at odds with the issue of profit margin given that carbohydrate and fat sources are cheaper than animal-based protein sources.
When looking at the ingredient list on a label, it is very important to keep in mind that the label tells us nothing about the amount of each ingredient. This is where the issue of composition (discussed below) helps us out.
For instance, if you see species-inappropriate, ingredients such as rice, potatoes, peas, broccoli, blueberries, etc., on the label, you know that the amount of these inappropriate items must not be very high if the carbohydrate level is low.
On the other hand, if we are dealing with a known allergy to any ingredient, we do not want that ingredient to be present in any amount so that is where the ingredient label does provide value.
Here are a few general guidelines that I like to focus on:
- Feed canned food only (or homemade) – no dry food.
- Stick with poultry (chicken and turkey) and rabbit as the bulk of your cat’s diet.
- I like to see liver in the diet but not as the first ingredient. Liver is high in vitamin A and D which can be overdosed. Liver only represents ~5% of a cat’s natural diet. Liver is cheap which is why it often appears first on the list in some diets.
- Fish – I do not feed fish to cats for the following reasons:
- high allergy potential (manifested as skin allergies or inflammatory bowel disease, and possibly asthma)
- toxin/mercury contamination
- PBDEs (fire retardant chemicals) – PBDEs are potent thyroid disruptors
- often high in phosphorus and magnesium
- highly addictive – the cat will not eat anything else
If you want to feed a fish-based food as a treat, please limit it to once or twice a week. (I do not feed any fish to my cats.)
- Beef is another food allergen for some cats but many cats do just fine with beef.
- Think ‘feathers and long ears’ and not as much ‘horns and fins.’
- Muscle meat (e.g., “chicken” or “turkey”) versus by-products is a debatable subject. See the by-product section below.
Be aware that most of the grain-free/by-product-free/muscle meat choices such as Wellness, Nature’s Variety, EVO 95%, etc., are high in fat and relatively low in protein in order to keep the profit margin high.
Given this fact, I can’t help but wonder if Friskies, 9-Lives, etc. (all by-products, no muscle meat) may actually be better diets because many of these by-product foods are higher in protein and lower in fat than the more expensive diets that are free of by-products.
High protein/low fat is especially important for cats trying to lose weight but do be aware that some of the highest protein by-product foods are high in fish and we do not want to feed a lot of fish as noted above so choose wisely.
See the Composition section below for more details.
- Moisture content: Here is where a company can really increase their profit margin. Most canned foods are ~78% water which helps keep a cat properly hydrated given their low thirst drive. This leaves 22% (100% – 78%) as dry matter (ie – food/calories/nourishment, fiber, and ash). I recently encountered a pouch food with 87.5% moisture. Subtracting 87.5% from 100% left only 12.5% dry matter. You can readily see that the food with only 78% moisture has nearly double the amount of dry matter in the can/pouch. Water is cheap yet this particular company is billing this 87.5% moisture-food as a “premium” food and is charging a premium price for it.
I have noticed that many of the products that come in pouches are very high in moisture content and are not giving you much ‘bang for your buck.’ Water is a critical nutrient but if you think your cat will benefit from more water in his diet than the usual 75-78% because he has urinary tract issues, you can just add water on your own.
Stick with foods that have a maximum guaranteed analysis figure of no more than 78% moisture so you are not paying a lot of money for water.
Note: I am trying not to make this subject too complicated. However, for the sake of completeness, I do need to mention ash (mineral) content. Ash is what his left over when all of the protein, fat, carbohydrates, fiber, and water are removed and is what remains after the cremation process of any living being. Ash is part of the ‘dry matter’ in the above example. The higher the ash content, the less actual food (calories) is in that dry matter.
Please don’t get bogged down with the issue of ash right now. However, understand that if you are comparing two foods with equal dry matter, the one with the lower ash value is going to give you more food (calories) in the can.
- Grains do not belong in cat food although I will discuss this issue in more detail below. They are there to add cheap bulk to the food and increase the profit margin of the company. When you see a food called “Chicken and Rice,” please understand that the rice is there to appeal to a human who is not educated regarding the cat’s obligate carnivore status. Please do not reward these companies by purchasing their products.
- Vegetables: Cats have no dietary need for vegetables yet companies play on the fact that the average person really does not understand the obligate carnivore status of the cat. Note that on, for one example, Hill’s Nature’s Best dry food there are 5 pictures: 1) rice 2) peas 3) wheat 4) carrots 5) fish or chicken.
Do you see that the above ingredients (1-4) are simply catering to what many humans perceive as healthy items to be included in their own diet? These first 4 ingredients add to the carbohydrate load of the diet (30% of calories in this case) and also represent a plant-based source of protein which you now understand is species-inappropriate for a cat.
Also note that wheat is a very hyperallergenic ingredient that does not belong in cat food. These ingredients simply increase the profit margin of the companies and are marketing ploys to get unsuspecting consumers to purchase their species-inappropriate diets.
In addition to the above issues, note that Hill’s does not put an ear of corn on the front of the bag since most people know that corn is not the most nutritious vegetable available yet if you look at the first ingredient in this food, it is cheap, species-inappropriate corn.
Why didn’t they put a picture of the very first ingredient – which makes up the bulk of the food – on the outside of their bag?
Another marketing ploy that Hill’s is now incorporating into their labeling is the substituting of the word “corn” with “maize.” Maize IS corn and since this company is well aware of the fact that consumers are becoming more savvy about pet food ingredients, they are now trying to disguise the corn in their diets by calling it “maize.” These deceptive marketing practices should be abhorred and certainly not rewarded with you purchasing dollars.
- Ingredient splitting
We all know that ingredients are listed in descending order by weight but that does not tell the whole story. Manufacturers are required to be very specific when naming their ingredients which works in their favor because it allows the grain fractions to be split up so that they are listed below the meat. Study this unhealthy ingredient list for Hill’s dry i/d:
Chicken by-product meal, brewers rice, corn gluten meal, whole grain corn, etc.
Many consumers will simply focus on the fact that “chicken” is the first word on the list. However, when all of the grain sources are added together, they often total more than the animal-based ingredient that is listed first.
Also consider that meat or by-products (not meals which are dry) are high in water weight and therefore lower in protein density. Grains are lower in water and higher in protein density. This means that diets like the one listed above derive most of their protein from plant sources. This would be fine if we were feeding cows or horses.
A note about ‘meals’: Yes, they are higher in protein by weight when compared to “chicken” but they are also heavily processed (cooked at a high temperature until ~95% of the water is gone). This intense processing destroys and alters nutrients.
Given the ‘ingredient splitting’ issue and the fact that most commercial canned foods contain some species-inappropriate ingredients, we have to look at the composition of the food to determine if it is a reasonably appropriate diet to feed.
Composition refers to the breakdown of the 3 basic food components that provide calories:
One of the most confusing aspects of food evaluations involve the terms:
- as fed (‘wet weight’)
- dry matter basis (‘dry weight’)
- metabolizable energy (ME) – calories that come from protein/fat/carbohydrate
The most accurate way to evaluate food is to consider the calories (ME) that come from the protein, fat, and carbohydrate fractions. This allows us to compare various diets without worrying about their different water (moisture) levels.
Keep in mind that the percentage of calories from protein/fat/carbohydrate must add up to 100%. Therefore, if you lower one fraction either one or both of the other fractions must rise. It is like a 3-way teeter totter.
If we want to keep the carbohydrates below 10%, that leaves 90% left over to split up between fat and protein. Given that animal-based protein is expensive and fat is cheap, it is not surprising that, in the interest of profit margin, pet food companies are now making high fat diets.
With the introduction of the ‘low-carb’ diets, in marched the high fat diets. However, on a good note, most cats do very well on the relatively high fat diets.
Important point: Cats are designed to process fats much more efficiently than carbohydrates.
When using the Cat Food Composition chart, the general rule is to look for choices that are ~ < 10% carbohydrates.
Next, look for one that is higher in protein (preferably ~40% or higher) and lower in fat (preferably ~50% or less).
Pet food labels
Unfortunately, pet food labels (“Guaranteed Analysis”) give us very little usable information regarding composition since they do not list the carbohydrate percentage and they only list the protein and fat and water in terms of minimums and maximums which are, by definition, inaccurate.
For instance, if a food states that the fat is a minimum of 6%, it could very well be much higher than that. Any value listed as a “minimum” or “maximum” is inaccurate and not very helpful.
Human food labels list the actually measured grams of protein, fat and carbohydrate – not just minimums and maximums.
All is not lost, however.
Let’s say you pick up a can of food that is free of grains (including whole grains and flours) and vegetables (including starchy potatoes). You know that this food is going to be very low in carbohydrates.
However, you still have no idea what the fat and protein levels are.
What is really crazy is that the pet food manufacturers are allowed to list fat as a ‘minimum’ – not a ‘maximum.’ This gives them free-rein to make high fat (read: high profit margin) pet foods.
An example using the can’s Guaranteed Analysis values follows:
I often hear people say that you can determine the carbohydrate content of a food by adding up the water (“moisture”) + protein + fat + fiber + ash and then subtracting the sum from 100%. Unfortunately, this can be extremely misleading in some cases.
Since profit margin is a pet food company’s number one priority, you can bet that the protein (expensive) will be pretty close to the minimum value listed on the can but the fat (cheap) may be much higher.
Let’s use Wellness canned Chicken as an example of how misleading the carbohydrate calculation from the label values can be:
- Protein (min) 10.0%
- Fat (min) 6.0%
- Fiber (max) 1.0%
- Moisture (max) 78.0%
- Ash (max) 1.8%
If you add up all of those numbers, you get 96.8%. Subtract this from 100% and you get 3.2% carbohydrates on a wet-weight basis. However, values should be considered on a dry matter basis (DMB). In order to convert that 3.2% into a dry matter basis, we must divide it by the dry matter in the food which, in this case, is at least 22%. I say “at least” because the moisture is listed as a maximum so it could be less than 78%. (100% – 78% moisture = 22% dry matter.) 3.2% divided by 22% = 14.5% carbohydrates on a DMB. Most of us would walk away from a food with that carbohydrate level.
However, when I obtained the more accurate measured values (versus minimums and maximums) from the company, it turns out that the fat content is closer to 11% – not 6% as listed on the label (as a minimum) and the protein was actually 12% not 10%. The moisture content was measured at 73% – not 78%. The wet-weight carbohydrates measured at 1.7% and the carbohydrates on a DMB were 6.5%.
So you can see by the above example (14.5% versus 6.5%) just how misleading it can be to try to evaluate the carbohydrate content by looking at the guaranteed analysis values on the can. When using the values on the can, the carbohydrate number came up at more than double the actually measured amount – and the fat content appeared to be about half of the actually measured amount.
However, keep in mind that all food products are going to vary from batch-to-batch so it is conceivable that one batch of Wellness Chicken may actually be closer to the 14% carbohydrates if the protein and fat amounts are closer to the minimums for that batch. The same is true for all of the numbers on the Cat Food Composition chart, although hopefully to a much lesser degree since the chart is based on ‘typical nutrient analysis’ figures – not vague minimums and maximums.
I often hear people get far too fixated on a chart’s numbers – comparing a food that is 3% versus 8% of calories from carbohydrates without realizing that the food marked “3%” today could be 8% with the next batch…..and the food marked “8%” could be 3% on the next batch.
Nothing in life is 100% consistent but I would much rather base my decisions on the ‘typical nutrient analysis’ values rather than the values found on the can under minimums and maximums.
Important point: Do not fall for labels that state “95% meat.” Why? Because “meat” can simply be high-fat meat trimmings. The word “meat” includes fat as well as protein so “meat” does not necessarily mean “high protein.” Keep in mind that lean meats go to the human market and the high-fat meat trimmings are routed to the pet food market.
Example: Natura EVO 95% Chicken & Turkey:
- Protein calories = 25%
- Fat calories = 73%
- Carbohydrate calories = 2%
Does this annoy me? You bet it does given how much some of these so-called ‘premium’ diets cost. Considering their price tag, it would be nice to see a higher protein/lower fat level – especially for any chubby cat that is on a weight loss program. Otherwise the cat can end up in a state of protein malnourishment when the calories are restricted for weight loss. (See my Feline Obesity page.)
However, as noted above, cats do not necessarily need diets that are >50% protein and <40% fat. For instance, years ago when I was involved with rescuing and adopting out cats and kittens, I fed them adult canned Wellness – Chicken or Turkey. (I used Wellness because it was available in 12 ounce cans which are more economical than the smaller cans.)
- Protein calories = ~30%
- Fat calories = ~65%
- Carbohydrate calories = ~5%
The cats and kittens all did well but as I have learned more about optimal feline nutrition, I would not choose a diet this low in protein and so high in fat.
Note that kittens do not need “kitten” food. They just need plenty of canned, species-appropriate (low carb/meat-based) adult food. Keep in mind that there are no mice running around in the wild with “kitten” or “adult” stamped on them. Kittens eat just what their parents eat – just more of it on a per-pound-of-kitten basis.
This is an area of controversy. However, by-products have a much worse reputation than they deserve. By-products are normal parts of a carnivore’s diet and consist of some very nutritious organ meats such as liver, spleen and kidney. On the other hand, by-products can also include feet and feathers which are of very low biological value. The problem is that it is impossible for the consumer to determine the quality of by-products contained in any food and the quality can vary with each company and batch of food.
As just stated, by-products that end up in cat food include very nutritious items but they also contain organs that have been deemed “unfit for human consumption.” Organs that show signs of disease such as cancer or infection are re-routed from the human meat market to the pet food market. The fact that cats eat by-products in the wild cannot be disputed. However, by-products that are consumed fresh ‘on the hoof’ are not the same as those that have been designated as unfit for human consumption. Therefore, the two situations are not entirely comparable.
That said, I strongly feel that the ‘anti-by-product’ movement has been taken to an extreme and I would much rather see a cat eat an all-by-product canned food than any dry food.
My preference would be to see muscle meat (“chicken,” “turkey,” etcera) as well as some by-products since that would mimic nature. Again, cats eat ‘by-products’ as part of their natural diet and who are we to say that we can omit liver, spleen, kidneys, etc., from a cat’s diet and not have them experience a potential deficiency?
The whole issue of by-products or no by-products is a personal one. We also have to pick our battles with our cats. For instance, many cats love Friskies, 9-Lives, and Fancy Feast varieties that contain by-products and we all know how picky cats can be and how important it is for them to eat – especially when they are ill or are diabetic and must eat on schedule.
On a personal note, my parents’ cat ate only Friskies canned food (Classic Pates – no gravy foods due to the higher carbohydrates) since he was rescued from the euthanasia list at our local shelter when he was 5 months old up until he was 18 years old. Tyke is now 20.5 years of age and has kidney disease so he is on a homemade diet but he is in great shape and still runs up and down the hallway like a kitten.
On a favorable note, at least by-products:
- are not hyperallergenic if coming from an animal the cat is not allergic to,
- do not contribute a carbohydrate load to the food, and
- are of animal origin – not plant origin.
It also makes much more sense to include some animal-derived by-products in a carnivore’s diet than it does to add potentially hyperallergenic, high carbohydrate grains like corn, wheat, rice, or soy.
Note that soy is also a thyroid disruptor and it has absolutely no logical place in cat food – especially given how common hyperthyroidism is in cats.
Cost and Quality
If you have read this entire page up to this point, you will understand how difficult it is to talk about the “quality” of pet foods.
On the one hand, we have the issue of by-product quality always being a big question/unknown, but on the other hand, the more expensive foods that are void of by-products are very high in fat and relatively low in protein.
So….it is a very frustrating trade-off.
That said, I will attempt to address this issue below.
Economics must be factored into any decision regarding what we feed our pets. The foods listed below can be quite expensive and may be outside of a person’s budget so let’s look at this further and prioritize things a bit. Of course all levels of quality can be mixed and matched according to a person’s budget and the needs – and always-picky taste buds – of the cat. Some cats really like the all by-products foods better than the foods without any by-products so this is where ‘taste bud negotiation’ comes into play.
If you want your cat to eat a by-product-free food but all he wants is Friskies or 9-Lives, play around with the percentage of each. He may eat the no-by-product foods at 80% if you mix in 20% of the with-by-product foods…..or 50:50….or……
Generally speaking, there are 4 basic categories of canned food:
- Products that contain all by-products and no muscle meat such as Friskies and 9-Lives. Please note that Friskies has started to add rice to some varieties of these foods which is very disappointing as it just adds carbohydrates to an otherwise low-carb food.
- Products that have a muscle meat listed as a first ingredient followed by by-products. Examples include some varieties of Fancy Feast. (Always read the labels because some flavors of Fancy Feast start with by-products as a first ingredient and do not list any muscle meat after the by-products making these varieties fit into category 1.)
- Products that contain only muscle meat and no by-products but also contain high carbohydrate ingredients such as grains, potatoes, peas, or other vegetables.
- Products that contain only muscle meat and no by-products or carb-contributing ingredients.
I would use the carbohydrate content as my guide – feeding the lowest carb choice. After considering carbs, look at the protein and fat amounts.
If the carbohydrate content of a food is high, that tells you that a substantial portion of the protein in the food may be coming from plants – not animals.
Remember that whole grains are a source of carbohydrates and protein. So if you see something like “whole grain corn” in the food, this tells you that some of the protein listed on the can is coming from plants, not animals.
While most canned foods are low in carbohydrates, the Hill’s Science Diet line of canned foods are notable exceptions. Many of these foods (both the prescription and non-prescription foods) are very high in carbohydrates and are not diets that I would recommend feeding.
For the math-inclined, I have added a section below showing two methods to roughly calculate the percentage of carbohydrates in food. You can skip this section if you plan to use the Cat Food Composition chart or plan to call the company for more accurate ‘typical nutrient analysis’ values.
Calculating the Protein, Fat, Carbohydrate Percentages
(Even though I discuss above just how inaccurate the labels are, I will include this section anyway. You can skip this section if you don’t want a headache.)
You will see conflicting carbohydrate values listed for the same food depending on how the value is calculated. There are three basic methods used to calculate the value of an individual nutrient:
- As a percentage of food weight (includes water)
- As a percentage of dry matter
- As a percentage of calories
When determining the carbohydrate content of a food, method 2 and 3 will yield roughly the same number.
Even though it is preferable to discuss nutrition in terms of the percentage of calories that a nutrient provides, most pet food manufacturers list their products’ nutrients in the form of percentage of weight.
Nutrient information may be listed in two different formats on the manufacturers’ websites. One is the guaranteed analysis (GA) figures (should be on all websites and on the side of the actual can of food). However, as discussed above, GA values are only minimums and maximums and can be very misleading.
The other format is the actual measurement of the ingredients in one (or more) sample of the food. These values more accurately reflect what is in the product.
Even though the GA values are not terribly accurate, they can provide a roughguesstimation of the contained nutrients.
To calculate the approximate weight of the carbohydrate in a food, add up the values for moisture, protein, fat, fiber, and ash and subtract this value from 100%. Here is an example from the PetGuard website for their Organic Chicken and Vegetable Entree:
Crude Protein 9.0% Min
Crude Fat 7.0% Min
Crude Fiber 1.0% Max
Moisture 78.0% Max
Ash 2.3% Max
If we add up the above figures, and then subtract this value from 100%, we come up with a rough idea of the carbohydrate content of this food: 3%.
But we are not finished yet. The value of 3% needs to be converted to a ‘dry matter basis’ (DMB) for accuracy. This calculation takes the water component out of the equation and then allows values for canned and dry foods to be comparable.
For the DMB value, we see that there is 78% water in this food. That leaves 22% as dry matter. If we take our 3% and divide it by 22% we come up with 14% carbohydrates (by weight) on a dry matter basis. With further calculations (see below) to compute the calories from carbohydrates, we come up with a value of 11%.
Calculating the percentage of calories from the carbohydrate part of the diet can be done with a few equations (shown below).
Again, less than 10% of a carnivore’s calories should be derived from a carbohydrate source.
When calculating the percentage of calories derived from the proteins, fats and carbohydrates we use the figures of 3.5 calories contributed by every gram of carbohydrate. For every gram of protein, 3.5 calories are provided and for every gram of fat, 8.5 calories are added.
For these calculations, you don’t have to worry about converting the values to DMB since the water content does not matter when looking at the percent-of-calories issue. (You must stay consistent, however, by using all figures leaving the water in [as fed or “wet weight”], or using all figures taking the water out [DMB]) This is the nice thing about ‘percent calories’ values – you can compare canned and dry food and not worry about the vastly different moisture content of the two types of foods.
We will use the PetGuard example above – keeping in mind the limitations for accuracy when using GA numbers:
Crude Protein 9.0% Min
Crude Fat 7.0% Min
Crude Fiber 1.0% Max
Moisture 78.0% Max
Ash 2.3% Max
We see that 9% of this food is made up of protein (9 grams of protein per 100g of food) so 9 X 3.5 = 31.5 calories from protein. Repeating the calculation for the 7% fat, we get 7 X 8.5 = 59.5 calories and from our calculations above, we know that this food is 3% carbohydrates. 3 X 3.5 = 10.5 calories from carbohydrates.
31.5 + 59.5 + 10.5 = 101.5 total calories per 100 grams of food
To calculate the percentage of overall calories from each food source, divide each amount by the total calories:
Protein: 31.5 divided by 101.5 = 31%
Fat: 59.5 divided by 101.5 = 59%
Carbohydrate: 10.5 divided by 101.5 = 10%
To double-check your math, add up the percentages to make sure they equal100%.
31% + 59% + 10% = 100%
Now…..go take some aspirin. :>)
Dusty and Dylan growing up together
I spent hundreds of hours during the summer of 2012 working to create the Cat Food Composition chart and I just repeated the task, updating the chart in March 2017. This was a daunting and incredibly time-consuming endeavor as it involved calling approximately 50 pet food companies – up to 4-6 times for many companies – and sending follow-up emails. After receiving the data, there was a lot of number crunching to be done.
It is important to understand that I only accepted typical nutrient analysis (TNA) data for the Food Chart – not guaranteed analysis (GA) figures which are only the minimums and maximums that are listed on the can. GA values, by definition, are inaccurate since there is no ceiling for a minimum and no floor for a maximum. A diet that is labled as having a minimum of 6% fat could actually be considerably higher. Fat should be required to be listed as a maximum, not a minimum, considering how cheap fat is. Pet food manufacturers should not be given free rein (with a minimum set but no maximum) to include so much fat in their diets which then leads to diminished protein levels.
The data required to be included on the Cat Food Composition chart is very basic. In fact, several companies have the information right on their website.
On the other hand, it was extremely difficult to get data from many of the companies. Several refused to provide it stating that it is “proprietary” information. This attitude shows a complete disregard for the consumer’s right to know what they are feeding their pet.
I will not use or recommend any products manufactured by companies that exhibit a lack of total transparency with respect to basic nutrient information. There are too many other companies to choose from that are more cooperative.
It is up to the reader to do their own research if they are interested in feeding a diet that is not on the Cat Food Composition chart. This means calling the company and requesting ‘typical nutrient analysis‘ (TNA) – not ‘guaranteed analysis’ (GA) figures which can be found on the can of food.
Also, since formulations (recipes) can change for any product at any time, it is up to the individual to call the respective companies if the most current information is desired.
Contacting Pet Food Companies
Unfortunately, it can be like pulling teeth to get usable information from pet food companies. Some companies are better than others but you have to be persistent with many of them.
If a company does not willingly divulge TNA information, then I will not use their products.
Use the following dialog when calling the companies:
“I would like to know the percentage of calories that come from protein, fat, and carbohydrates.” This is also known as the “metabolizable energy (ME) profile.”
If they do not have ME values, at least obtain dry matter values and you can calculate the ME yourself using the math (formula) tutorial above.
Stress that you do not want the GA figures as they are nothing more than minimums and maximums and this information (as it pertains to protein and fat but not carbs or phosphorus) is already contained on the can.
Again, values expressed as minimums or maximums are, by definition, inaccurate since there is no ceiling or floor with regard to the amounts.
If you have a cat with kidney or urinary tract problems, you will also want to ask:
“How many milligrams of phosphorus are in the food per 100 kcal?”
Many companies will give you the phosphorus value in terms of dry matter percentage and will not provide the mg/100 kcal value. As a point of reference, a value below 1% dry matter is favorably low.
This is a complicated subject that is impossible to cover in one webpage article. If the reader needs more detailed help, I am available for phone/Skype consultations.
The frustrations associated with:
- trying to pick a suitable commercial cat food based on the very limited information provided on pet food labels;
- the numbers of species-inappropriate ingredients contained in commercial foods, and
- the fact that the low carb choices are so high in fat and low in protein,
led me to start making cat food. I fully realize that this is not the direction that most people want to go in so I wrote this page in order to help the reader as much as possible.
Keep in mind that I am no more privy to the inner workings of any of these companies than the reader. I am at the mercy of what they put on their websites or provide verbally – just like all of you are.
One ingredient that has caught my attention lately is carrageenan. If one does a PubMed search of carrageenan, they will find many references to “carrageenan-induced inflammation” which is very disturbing in light of how common IBD (inflammatory bowel disease) is in cats. Please see this link to an interesting study showing carrageenan to be an inflammatory mediator in human intestinal cells.
Unfortunately, many commercial canned products contain carrageenan. If your cat has chronic diarrhea or vomiting, I suggest trying to find a food without this ingredient listed but just know that your choices will be limited.
Do Not Recommend
The following is a list of companies that were not forthcoming with TNA data for their products. Given that there are plenty of other choices on the market, the consumer should not support companies that do not respect the consumer’s right to quickly and easily obtain vital nutrition information.
Authority (Petsmart private label)
Good Natured (Petsmart private label)
Grreat Choice (Petsmart private label)
Simply Nourish (Petsmart private label)
Nutrisca (Dogswell brand)
Feline Natural (K9 Natural)
Raw Meat and Bones – “Balanced” Diets
6/23/16 – general comments:
Notice that I put the word “balanced” in quotation marks. The dialog below will address this issue as it relates to the bone content of with-bones diets because many of these commercial products are not properly balanced with respect to the amount of bone included.
As noted above, I am not any more privy to information about commercial pet foods than the reader is. I am not a ‘fly on the wall’ in these companies’ manufacturing plants. I have no idea how clean or contaminated their process is and I have no idea how much bone material is included in these diets. The first part (contamination) does not worry me as much as the second issue (bone content) which I am addressing here.
Important point: The more bone material that is contained in the product, the higher the profit margin is for the company.
In a nutshell, when feeding some (which ones??) of the commercial with-bones diets to our cats, we are forcing them to consume far more bone material than they would be eating in the wild.
Think about it: When you watch Nat Geo Wild and you observe a lion take down a cape buffalo and eat it, that lion walks away leaving close to 100% of the skeleton (bones) behind for the smaller animals/vultures to pick over. They consume very little bone material.
Now look at the other end of the spectrum – the small, wild or domestic, cat that eats a whole mouse or bird – meat and all, or most, of the bones.
When the two are compared – large and small cats – you can see that there is a wide variation in bone consumption. However, the larger the prey animal (buffalo vs mouse), the higher the bone-to-meat ratio so the small cat is not consuming as much bone (relative to the meat) when it eats a mouse when compared to a lion eating an entire cape buffalo.
So how much bone material relative to muscle meat/organs is optimal for our small cats to consume? I don’t know that there is a correct answer to that question but I do know that the range is wide and some cats may be able to handle more bone material than others.
But what does “handle” really mean? Does it mean that they are barely dodging the constipation ‘bullet’ or are lucky enough to not end up with a life-threatening urethral obstruction due to too much bone (minerals) in their diet?
My strong feeling is that cats should not be fed ground up whole carcasses (e.g., rabbit, chicken, duck, etc.) because it forces them to eat more bone material than is optimal/safe.
The more bone material contained in the diet, the more minerals are filtered through the kidney and end up in the bladder. Minerals (calcium, phosphorus, magnesium, etc.,) are building blocks of crystals/stones which can obstruct the ureter or the urethra – especially in male cats since their urethra is longer and narrower than a female’s urethra.
I am EXTREMELY passionate about, and sensitive to, the tremendous amount of suffering that cats with urethral obstructions have to endure. Many “blocked” cats end up with a ruptured bladder resulting death. The process is slow and painful.
But if the patient is lucky enough to be taken to a veterinarian before it loses its life? Well, the client is faced with a huge vet bill and the patient must endure being catheterized (often more than once) and several days in the hospital in a very unhappy state.
See Opie’s story and pictorial here to witness the suffering that a blocked cat must endure.
Next, many veterinarians drastically ‘jump the gun’ and start talking about penis amputation (perineal urethrostomy) before the poor cat is given a fighting chance to keep his penis and go forward being fed a more appropriate diet.
Also understand that because bones contain a lot of phosphorus, the typical with-bones diet is unsuitable for cats with chronic kidney disease.
If you have visited this page in the past, you will note that I have removed all names of the raw/with-bones diets that were listed here previously. Since I have no idea what the bone-to-meat ratio is in any of these diets, no product names will be listed here.
If you are tempted to write to me asking which raw/with-bones diet I would recommend, please don’t. I have not taken the time to scrutinize (including calling the companies) the dozens of options on the market and, as stated elsewhere on this webpage, I make my own cats’ food so that I can control the bone content, etc. I am not interested in feeding any of the commercial raw/with-bones products to my cats.
All that said, I am sure that there are many healthy, well-balanced (with respect to bone-to-meat ratio) products on the market but which ones fall into that category? It is up to the reader to do their own research and come to their own conclusion.
Otherwise, please see my Making Cat Food page.
Even though I am hoping that you have read my Feeding Your Cat: Know the Basics of Feline Nutrition article and will not be feeding any dry food in the future, I had to add a link to this commentary on the ‘breed-specific’ dry foods that are currently being marketed by companies obviously desperate to gain more market share by hoping that the consumer will actually believe the absurd claims that they make regarding these diets. Please see this link for more information.
Partially Updated March 2017
Lisa A. Pierson, DVM