Are Eggshells Good for a Dog's Coat?

Because meat is high in phosphorus and low in calcium, any dog fed an all-meat diet that doesn't contain bone needs a calcium supplement. Even one fed a mixed cooked diet without bones could use a calcium boost. Experts continue to debate the ideal ratio of calcium to phosphorus for dogs; some say it should be 1:2, while others advocate as high as 2:1. This may be a case in which too much is better than not enough. While excess calcium can cause bone problems in growing puppies, a deficiency can cause worse systemic ones in both puppies and adult dogs.

If you choose to give your dog a commercial calcium supplement, try to find one that contains no phosphorus at all. Bone meal is better than nothing, but be careful to buy it at the pet store and not at the garden center -- bone meal fertilizer can kill your dog. A good and readily available source is calcium carbonate, which you can buy in the form of antacid tablets used for indigestion. Best of all is powdered eggshell, which is free if you eat eggs yourself or feed them to your dog.

You can use any kind of bird egg shells to make a canine calcium supplement -- chicken, duck, goose, pheasant or even ostrich -- as long as you have the capability to render them into powder. Chicken eggs are probably the most available. Organic local eggs fresh from the farm, or at least the farmers' market, are the best, but store-bought cold-storage eggs will do if you wash the shells off to remove any coating. One large chicken eggshell yields about a teaspoon of powder containing slightly less than 800mg of absorbable calcium, and that amount will balance out the phosphorus in 2 pounds of boneless meat. Wash and oven-dry eggshells and powder in a coffee grinder for a home-made calcium supplement.

The part of the egg that will benefit a dog's coat is the yolk. It contains essential fats -- especially omega-3 fats -- and vitamin B7 (aka biotin), both of which can improve a dog's coat texture and shine. Limit them to a couple a week, though, as they are also high in calories. Cooking doesn't affect the nutrients, so you can feed them raw, scrambled or hard-boiled, according to your dog's preference.