Understanding Canine Nutrition, part 2
Written by: Maryann Szalka
Last month 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.
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!
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.)
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).
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!