There are differences between the dog and human in their use of carbohydrates. This includes the use of different forms of carbohydrates from starch or sugar. For example; we know sugar forms of lactose, dextrose or glucose are all different as dietary sources of carbohydrates. These can be stored or used as an instant energy supply by a human. Also, we know how a human stores carbohydrates from some starch sources better than sugar sources for future energy requirements. Only the human can store dietary carbohydrates for later conversion into energy. Canines turn all dietary carbohydrates, from any source, into instant energy, and none is stored for energy requirements that develop later.
Also, for all types of dogs, all forms of sugar carbohydrates have been found to be detrimental, except for lactose found in the milk of a lactating bitch for her puppy. Please Note; this form of lactose is not the same as a synthetic lactose from sugar beet or sugar cane or even the lactose found in the milk of other species of mammals.
Like the sugar carbohydrates of lactose, glucose and dextrose being different, carbohydrates found in animal fat, vegetable and grain sources (soy bean, beet pulp, wheat, rice, potatoes or corn) are all different. These differences are important. One study cited in the NRC publication Nutrient Requirements of Dogs shows that the digestible fat from one source provides 2.25 times the metabolizable energy concentration of digestible carbohydrate than from a second source. Another study cited showed different breeds of dog need different amounts of carbohydrates or different carbohydrate to protein ratios in their food. Therefore, if your dog is requiring a high carbohydrate diet due to breed requirements or life-style, you need to provide those carbohydrates in the proper amount and from the proper source.
When you are considering which food source of carbohydrates contains the proper form for your dog, you should consider the type of food sources that were in the native environment for your breed. Then also
remember to eliminate those sources that would have been foreign to that breed's native environment. A dog breed from Ireland, where potatoes or flax were common dietary sources of carbohydrates, would not have been exposed to rice.
Yet a dog breed from China could have been exposed to several different types of rice that were grown as common sources of dietary carbohydrates in its environment. A dog breed from a mountain environment, where both vegetable and grain crops are scarce, could have a different need for its carbohydrate source as well. Some mountain breeds of dog may not utilize potato or rice carbohydrate any better than a sugar, but best use an animal fat form of carbohydrate.
Animal fat is one of the most common carbohydrate sources found in commercial dog food and because a food contains animal fat, it is often assumed it is providing dietary fatty acids. Normally this is not so since
animal fat in dog food is exposed to extremely high temperatures during processing procedures. The high temperature can eliminate the polyunsaturated fatty acid content of the rendered fat. In many cases manufacturers use separate food sources to provide fat carbohydrates and polyunsaturated fatty acids in their foods. The better commercial dog food manufacturers use grain or vegetable oils that have been cold pressed or processed to retain the needed polyunsaturated fatty acids.
These cold pressed grain and vegetable oils still contain the fatty acids known as the alpha-Linolenate family. There are three fatty acids that make up the entire alpha-Linolenate family; oleic acid, linolenic acid, and linoleic acid. With breeds that produce skin oil, the requirement for the oleic acid part of the alpha-Linolenate family is higher than with the breeds that do not produce skin oils. However, it is essential for all dogs to receive all three of these fatty acids to produce the arachidonic acids they all require. Since these fatty acids are a complete nutritional team, they should be listed on labels in the same way that manufacturers of premium foods list the amino acid content of their food's protein.
Manufacturers who list all three on the label provide you with a more accurate statement of the package contents. This labeling practice enables you to choose more intelligently the proper food for your specific breed of dog.
In processed dog foods animal fat should be considered as only a source of dietary carbohydrates. After the rendering process, it contains very little of the alpha-Linolenate fatty acids. A complete diet for most breeds of dog should contain both animal fat and a source containing the alpha-Linolenate family of polyunsaturated fatty acids. Do not assume fatty acids are present just because the dog food label has fat listed. The finished product may or may not have any fatty acids. Commercial food manufacturers may add animal fat just for its carbohydrate content or to make it more palatable for most canines.
Also do not assume that the product contains all three of the fatty acids of the alpha-Linolenate family if the label only lists Linoleic acid. This one fatty acid can be purchased separately as a raw material for dog food. Both carbohydrates and fatty acids are important and both must be provided in dog foods. However, you must use a source of carbohydrates or fatty acids that can be assimilated by the breed of dog you are feeding.
An indicator that your dog is rejecting food carbohydrates from sugar, grains, vegetables or animal fat in the food is persistent diarrhea. The indicator that your dog is not assimilating the fatty acids is a loss of coat shine or a loss in the skin's elasticity. Therefore, it is easy for the dog owner to see a dietary carbohydrate or fatty acid nutritional problem. Conversely, it is also easy to see when foods are supplying the proper sources and amounts of these important nutrients.