Dr. Pitcairn's Complete Guide to Natural Health for Dogs and Cats by Richard H. Pitcairn, Susan Hubble Pitcairn

the plants can’t “grab” it. Thus, the long-term effect of acid rain is lowered mineral content of plant foods.
    Another factor is that even under the best of conditions, it takes time for the plant to absorb the minerals. Under modern conditions, in which artificial fertilizers are used to accelerate the growth of plants, the time for mineral absorption is less, which leads to low mineral levels. Of course these two factors work together, and the net result is less mineral content with time. The Earth Summit Report of 1992 revealed that North American farm and range soils had been depleted of over 85 percent of their minerals.
    For animals that are not in the best of health, mineral supplements are an essential part of the diet. Another reason I recommend supplements is to balance the ingredients of the recipes given in this book so that they meet the nutritional standards for dogs and cats for such important nutrients as calcium,iron, linoleic acid, vitamin A, and the B vitamins set by the Association of American Feed Control Officials. So don’t think of supplements as something optional. They are an integral part of each recipe (unless noted otherwise).
    The basic supplements described below are usually included in each recipe. Following is a summary of the purpose of each supplement, as well as various supply sources, and instructions for preparing the supplement for inclusion in the diet.
    C ALCIUM S UPPLEMENT
    Some supplemental source of calcium is an essential ingredient in every recipe. Also, every recipe should have a proper calcium/phosphorus ratio. Though there is a wide range of what can support health, it is optimal if the ratio of calcium/phosphorus for dogs is between 1.2 and 1.4 parts calcium to 1 part phosphorus—thus, a little more calcium than phosphorus in the diet. Cats do better with a ratio of 1 part calcium to 1 part phosphorus.
    I hasten to add that there is considerable flexibility in this. Most animals will do just fine with a wide range from 1 to 2 parts calcium to 1 part phosphorus. The actual amounts in food prepared is difficult to determine exactly. Generally, the minerals from bones or pure calcium sources are readily absorbed by the body, while those from plant sources may be less digestible. For example, only about 30 percent of the phosphorus in grains is available to the body. The recipes in the next chapter are calculated to include the minerals in the foodstuffs as well as what is added from bone meal, with the assumption that most will be absorbable.
    Here are some ways to add this calcium.
    Bone Meal
    Buy the powdered bone meal that is sold for supplementation of animals. You can use that sold in natural food stores for human use but it will be less convenient and more expensive. The quality is the same—that is, not from U.S. livestock—and the advantage of the animal products is the availability in powder form to add to the food. These products come from purer sources than the bone meal sold in garden-supply departments—which is never to be used as a food.
    Bone meal is the most natural calcium source for carnivores and provides many trace minerals. It is also a convenient, easy to use, and very concentrated form of calcium. It contains phosphorus as well as calcium, but in the recommended amounts there is plenty of extra calcium to balance out the phosphorus. Bone meal is the best choice when feeding large dogs, especially those with bone problems or signs of hip dysplasia. There are several brands available, and they vary somewhat in calcium concentration. See the Table of Calcium Supplementation Products .
    Seaweed
    Animal Essentials has provided a form of calcium derived from seaweed growing off the coast of Ireland. It is a very pure form of calciumand has the advantage of not coming from an animal source. It also provides many excellent trace minerals.
    Di-calcium Phosphate
    For those people who prefer not to use animal products but who want a higher combined amount