Understanding Canine Nutrition (Part II)

This article appeared in the Bagpipes in February 2006.

Earlier you read about protein, carbohydrate, fat, fiber, vitamins and minerals; and now it’s time for a pop quiz! If you feed a commercially prepared dog food, go and get the bag. (Take your time, since many of you will have to lug out that 40 lb bag of food from the pantry or basement). Okay, are you ready? Review the list of ingredients and see if you can categorize everything the manufacturer put in that bag. Just for fun, I’ll join you. I have the label from the brand of dry food I feed to my Beardies, but for legal reasons, I won’t mention the brand name.

Ingredients
Deboned Chicken, Chicken Meal, Oatmeal, Ground Barley, Ground Brown Rice, Rice Bran (from brown rice), Rye Flour, Canola Oil (preserved with mixed tocopherols, a natural source of vitamin E), Whitefish, Tomatoes (natural source of lycopene), Natural Chicken Flavor, Flaxseed, Ground Millet, Carrots, Apples, Spinach, Blueberries, Sweet Potatoes, Calcium Carbonate, Dicalcium Phosphate, Potassium Chloride


Minerals
Zinc Sulfate, Zinc Proteinate (a chelated source of zinc), Iron Proteinate (a chelated source of iron), Ferrous Sulfate, Copper Proteinate (a chelated source of copper), Copper Sulfate, Manganese Proteinate (a chelated source of manganese), Manganese Sulfate, Sodium Selenite


Vitamins
Choline Chloride, Beta-Carotene, Vitamin E Supplement, Ascorbic Acid, Vitamin A Supplement, Niacin, Calcium Pantothenate, Riboflavin, Vitamin D-3 Supplement, Pyrodoxine Hydrochloride, Thiamine Mononitrate, Folic Acid, Biotin, Vitamin K Supplement, Vitamin B-12 Supplement, Chicory Root Extract, Glucosamine-HCl, Chondroitin Sulfate, Garlic, Taurine, Yucca Schidigera Extract, Green Tea Extract, Lactobacillus plantarum, Enterococcus faecium, Lactobacillus casei, Lactobacillus acidophilus.

Guaranteed Analysis

Crude Protein
Not Less Than
22.0%

Crude Fat
Not Less Than
12.0%

Crude Fiber
Not More Than
3.0%

Moisture
Not More Than
11.0%

Vitamin E
Not Less Than
150 IU/kg

Omega 6 Fatty Acids*
Not Less Than
2.70%

Omega 3 Fatty Acids*
Not Less Than
0.80%

Beta-Carotene*
Not Less Than
5 mg/kg

Lycopene*
Not Less Than
0.25 mg/kg

Taurine*
Not Less Than
0.09%

*Not recognized as an essential nutrient by the AAFCO Dog Food Nutrient Profiles.


That’s a lot of information to digest (pun intended), so what does it all mean? First we’ll begin by looking at each ingredient and learn what role it plays in your dog’s nutritional intake. Then, we’ll calculate just how much protein, fat, carbohydrate and fiber is in this bag. Last, we’ll find out what isn’t in this bag of dog food!

Ingredients Primary Role Additional comments
Chicken and Chicken Meal Protein High quality protein
Oatmeal Carbohydrate Also a source of protein and fiber
Ground Barley Carbohydrate Also a source of fiber
Ground Brown Rice Complex Carbohydrate Good source of B vitamins
Rice bran Fiber  
Rye flour Carbohydrate  
Canola Oil Fat Rich source of essential fatty acids
Whitefish Protein Also a source of Omega 3 fatty acids
Tomatoes Carbohydrate Source of Vitamin C and lycopene
Natural Chicken Flavor Improves taste Made from chicken liver
Flaxseed Fiber Rich in Omega 3 fatty acids
Ground Millet Carbohydrate High in fiber and B complex vitamins
Carrots Carbohydrate Source of fiber and Vitamin A, beta-carotene
Apples Carbohydrate Source of fiber, Vitamins A and C
Spinach Carbohydrate Source of potassium, iron, Vitamin C
Blueberries Carbohydrate Source of Vitamins A & C, potassium
Sweet Potatoes Complex Carbohydrate

Source of fiber and beta-carotene

 

Minerals

 

Comments

 
Zinc Sulfate
Source of Zinc
 
Zinc Proteinate* Source of Zinc  
Iron Proteinate* Source of Iron  
Ferrous Sulfate Source of Iron  
Copper Proteinate * Source of Copper  
Copper Sulfate Source of Copper  
Manganese Proteinate* Source of Manganese  
Manganese Sulfate Source of Manganese  
Sodium Selenite Source of Selenium not a significant source of Sodium


* Chelation binds the mineral to an amino acid. This may increase the bioavailability of some minerals, but have no effect on other minerals, and may actually diminish it in some cases

Vitamins Comments

Choline Chloride* A synthetic source of choline, a essential nutrient
Beta-Carotene* An anti-oxidant
Vitamin E Supplement Added to most pet foods as a vitamin source
Ascorbic Acid Vitamin C
Vitamin A Supplement Added to most pet foods as a vitamin source
Niacin Vitamin B3
Calcium Pantothenate A synthetic source of Vitamin B5
Riboflavin A synthetic source of Vitamin B2
Vitamin D-3 Supplement Added to most pet foods as a vitamin source
Pyrodoxine Hydrochloride A synthetic source of Vitamin B6
Thiamine Mononitrate A synthetic source of Vitamin B1
Folic Acid Vitamin B9
Biotin A natural B Complex vitamin
Vitamin K Supplement Added to most pet foods as a vitamin source
Vitamin B 12 Supplement Added to most pet foods as a vitamin source, B12 is Cynocobalomin
Chicory Root Extract* A prebiotic that serves as a food source for probiotics
Glucosamine An amino sugar, play a roles in cartilage formation and repair
Chondroitin Sulfate* Part of a large protein molecule that gives cartilage its elasticity
Garlic* Has antibacterial, antifungal, and antiviral properties
Taurine* Similar to amino acids, essential for heart health
Yucca Schidigera Extract* Rich in minerals, has anti-inflammatory properties, aids digestion
Green Tea Extract* A highly active antioxidant
Lactobacillus plantarum*

Natural micro-flora (good bacteria) that may help digestion

Enterococcus faecium* Natural micro-flora (good bacteria) that may help digestion
Lactobacillus casei* Natural micro-flora (good bacteria) that may help digestion
Lactobacillus acidophilus* Natural micro-flora (good bacteria) that may help digestion


*By definition, these items are not vitamins, although the manufacturer has decided to list them in under this heading.

Dog foods differ primarily in their source of protein, and a premium dog food will contain a high quality source(s) of protein. The percentage of protein tells you nothing about the quality and digestibility of the product. See the table below to compare the approximate digestibility of the more common dog food ingredients. Egg white protein is used as the benchmark, giving it a value of one (1) since it is so highly digestible. Other protein sources are then compared to egg whites as to their digestibility. This brand uses a high quality of protein, and uses wholesome grains, rather than grain by-products or corn (which is a low quality protein source often used as a filler; and as we have recently heard in the case of the contaminated Diamond® dog food, can be a source of the toxic fungal mold aflatoxin.)

Table 1 – PROTEIN DIGESTIBILITY LIST

Egg whites 1.00
Muscle meats (chicken, beef, lamb) .92
Organ meats (kidney, liver, heart) .90
Milk, cheese .89
Fish .75
Soy .75
Rice .72
Oats .66
Yeast .63
Wheat .60
Corn .54


(Note: Values in table are approximate, as they have been taken from several nutrition sources.
From: Pet Nutrition Principles by T. J. Dunn, Jr. DVM 

You should know that the weight of ingredients determines the order in which they are listed on the label, but this can be misleading. The rules regarding labeling allow the manufacturer to list ingredients with the same weight together, but the manufacturer can choose the order.

If you read the guaranteed analysis portion of the label, you will notice that the word carbohydrate is missing. (Actually pet food regulations do not allow the word carbohydrate on the label.) Fortunately they do provide the information you need to do the calculation. You may or may not see Ash listed in the guaranteed analysis. Ash is what remains after the food is burned, and the typical content is between 5% and 8%. The amount of fiber is not used in the calculation, since fiber really is a carbohydrate, but you learned that last month! Incidentally, the word crude refers to the total protein content, and not necessarily the amount of protein that is actually digestible. The actual amount depends on the source of the protein used in making the kibble (See Table 1).


The equation below will help you to calculate the percentage of carbohydrate.

100% - % of crude protein - % of crude fat - % of moisture – % of ash = % of carbohydrate

By using the information from my label, this is how I could calculate the percentage of carbohydrate in this particular brand of dog food.

100% - 22% - 12% - 11% - 6% (average ash content) = 49%

According to an article titled Your Dogs & Cats Need Meat NOT Dried Food by Beth Taylor and Steve Brown, “We think it’s wise to add fresh meat to dry foods. Dry foods are high in carbohydrates and lower in protein than is the natural diet of dogs and cats. Meat adds protein, and therefore decreases the percentage of carbohydrate.” The natural diet of a dog has about 14% of its calories (5-8% by dried weight) coming from carbohydrates, while a typical dry food derives more than 50% of its calories from carbohydrates. When adding more protein, be sure to decrease the amount of kibble, so you are not providing too many calories.

Just as important as what goes into your Beardie’s food, is what does not go in! So what’s not in the food I feed my dogs? If you read the label you will not find the following ingredients; meat or poultry by-products, rendered animal fats, wheat, corn, soy, white rice, artificial preservatives, added sugar or added salt, artificial flavors, artificial colors or dyes. FYI, by-products may include spleens, brains, blood, feet, heads, feathers or animal tissues that don’t fit in any other category. And because manufacturers need to ensure that dry foods have a long shelf life, fats used in kibble are preserved with either synthetic or natural preservatives. Synthetic preservatives include butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT), propyl gallate, propylene glycol (also used as a less toxic version of automotive antifreeze), and ethoxyquin. The use of these chemicals in pet foods has not been thoroughly studied, but evidence suggests that long term accumulation in the body may be ultimately harmful. However, some manufactures are now using natural preservatives such as Vitamin C (ascorbate) and Vitamin E (mixed tocopherols) to preserve the fats in their product, making these brands a potentially safer choice for your Beardie.  This might be a good place to mention that dog food does deteriorate with storage and you should always check the manufacturing date (or sell by date), and keep it in an airtight container once the bag has been opened, not buy more than you can use in a couple of weeks, and understand that even then there will be some loss of nutrients, especially fats.  This is why if you add just one thing to your kibble it should be a good source of essential fatty acids.

For comparison, I have copied information from another dog food label. Looking at the guaranteed analysis, it would appear these two brands are quite similar until you read the actual list of ingredients! This second brand is definitely not a premium dog food, but one that can be found on the shelf of almost every grocery store across the US. I have underlined some of ingredients that should concern a savvy consumer. Corn, which is not a very digestible source of protein, is the primary ingredient, and it’s all down hill after that. Did you notice the amount of moisture was 18%? The ingredients list “water sufficient for processing” before the word “beef”. And what exactly is “animal digest”? Animal Digest - A powder or liquid made by taking clean, un-decomposed animal tissue and breaking it down using chemical and/or enzymatic hydrolysis. The animal tissues used shall be exclusive of hair, horns, teeth, hooves and feathers, except in such trace amounts as might occur unavoidably in good factory practice and shall be suitable for animal feed. If it bears a name descriptive of its kind or flavor(s), it must correspond thereto (i.e., chicken digest). Animal Digest is a cooked-down broth made from unspecified parts of unspecified animals. Any kind of animal can be included: goats, pigs, horses, rats, etc. The animals can be obtained from any source, so there is no control over quality or contamination.


In addition, this food contains a lot of chemicals, added sugar and salt, and food dyes (artificial coloring).

Ingredients
Corn, soybean meal, ground wheat flour, beef and bone meal, animal fat (BHA used as preservatives), corn syrup, wheat middlings, water sufficient for processing, beef, animal digest, propylene glycol, salt, hydrochloric acid, caramel color, potassium chloride, sorbic acid (used as a preservative), sodium carbonate, choline chloride, minerals (ferrous sulfate, zinc oxide, manganous oxide, copper sulfate, calcium iodate, sodium selenite), titanium dioxide, vitamins (vitamin E supplement, niacin supplement, vitamin A supplement, d-calcium pantothenate, riboflavin supplement, pyridoxine hydrochloride, thiamine mononitrate, vitamin D3 supplement, folic acid, biotin, vitamin B12 supplement), calcium sulfate, red 40, yellow 5, yellow 6, BHA (used as a preservative), dl-methionine.


Nutritional Information
CRUDE PROTEIN
19.0% MINIMUM

CRUDE FAT
8.0% MINIMUM

CRUDE FIBER
4.0% MAXIMUM

MOISTURE
18.0% MAXIMUM

CALCIUM
1.0% MINIMUM

PHOSPHORUS
0.80% MINIMUM

POTASSIUM
0.80% MINIMUM

ZINC
125 mg/kg MINIMUM

VITAMIN A
5100 IU/kg MINIMUM

VITAMIN D
500 IU/kg MINIMUM

Bottom line, you get what you pay for. Premium foods typically contain higher quality (protein and carbohydrate) ingredients and avoid the use of artificial colors and preservatives. In fact, many of the artificial colors used in dog foods have been associated with potential health problems. Artificial colors and “cute” shapes are added to appeal to the owner and not the dog. Do you really believe your dog thinks that little treat is really a mini pizza or a real piece of pepperoni! Be an informed consumer. This means; do your research, read labels, and make an informed choice. In the end, you may have a healthier Beardie!

Copyright © 2007 by Maryann Szalka. All Rights Reserved. Contact Maryann for reprint permission.