The important thing to keep in mind is that in order to be balanced a dog’s diet requires protein, carbohydrate, and fat, just as do the diets of human beings and all other dog. A safe general rule is to have 14 percent protein as a minimum (dry basis); 20 percent fat, and the balance carbohydrate and minerals with some indigestible residue. These essentials, in their proper proportions, can be supplied easily and inexpensively.
Fat in the Dog’s Diet. Let us stress again the fact that dogs can handle to advantage much more fat than most people give them. Idle dogs can utilize as much as 25 percent fat in their diets, whereas hard-working dogs, such as those drawing heavy loads in the Arctic, are often fed diets with 70 percent fat.
“Fat burns in the flame of carbohydrates.” Fat and protein alone are not as well tolerated by a dog as fat and protein with carbohydrate. Everyone knows that a fatty steak eaten alone soon becomes sickening, but that when bread or some other starch is taken along with it much fatter can be enjoyed. If all starchy foods are omitted, the proportion of fat should he lower.
Carbohydrates are so often locked up by nature that foods containing them need preparation if they are to be of most value to any dog. Starch granules are broken down by heat; heat also reduces starch to dextrose – one further step in the digestive process. It is amusing to hear dog owners say that they never feed their dogs starch and in the same breath announce that they give them lots of dog biscuits – which are mostly baked starch.
Carbohydrate is found in liver in the form of glycogen (dog starch), and this, too, is digestible. Many starches are locked up in cellulose (the chief component of the cell walls of plants). Heat helps break down cellulose so that dogs can digest the starch. Carrots, potatoes, turnips, and other vegetables; apples, pears, and other fruits are often relished in their raw state by dogs, but much of what is eaten is found in an undigested state in the stool. Boiled or baked, and then mashed, these foods are assimilated almost entirely.