In developed countries, nutritional diseases are rarely seen in dogs, especially when they are fed good quality, commercial, complete and balanced diets. Nutritional problems occur most commonly when dogs are fed imbalanced homemade diets or certain human foods. Dog foods or homemade diets derived from a single food item are inadequate. For example, feeding predominantly meat or even an exclusive hamburger and rice diet to dogs can induce calcium deficiency and secondary hyperparathyroidism.
Nutrient deficiencies have also been seen in dogs and cats fed vegetarian diets. If pet owners wish to feed their pets homemade diets, the diets should be prepared and cooked using recipes formulated by a veterinary nutritionist.
Wrong fed dogs may suffer from micro and macroelements deficiencies
Minerals can be classified into three major categories: macrominerals (sodium, potassium, calcium, phosphorus, magnesium) required in gram amounts/day, trace minerals of known importance (iron, zinc, copper, iodine, fluorine, selenium, chromium) required in mg or mcg amounts/day, and other trace minerale that have an unclear role in companion animal nutrition (cobalt, molybdenum, cadmium, arsenic, silicon, vanadium, nickel, lead, tin). A balanced amount of the necessary dietary minerals is important.
Macrominerals:
Calcium and phosphorus deficiencies are uncommon in well-balanced growth diets. Exceptions may include high-meat diets high in phosphorus and low in calcium and diets high in phytates, which inhibit absorption of trace minerals. In dogs the requirements for dietary calcium and phosphorus are increased over maintenance during growth, pregnancy, and lactationI. Insufficient supplies of calcium or excess phosphorus decrease calcium absorption and result in irritability, hyperesthesia, and loss of muscle tone, with temporary or permanent para lysis. Skeletal demineralization, particularly of the pelvis and vertebral bodies, develops with calcium deficiency. Often, there is a history of feeding a diet composed almost entirely of meat, liver, fish, or poultry.
When calcium or phosphorus supplementation is excessive, insoluble and indigestible mineral complexes form within the intestine and may decrease magnesium absorption. Clinical signs of magnesium deficiency in puppies are depression, lethargy, and muscle weakness. Excessive magnesium is excreted in the urine.
Microminerals:
Iron and copper found in most meats are used efficiently, and nutritional deficiencies are rare except in animals fed a diet composed almost entirely of milk or vegetables. Deficiency of iron or copper is marked by a microcytic, hypochromic anemia and, often, by a reddish tinge to the hair in a white-haired animal. When high-meat diets are used may be seen Iodine deficiency. Deficiency of zinc results in emesis, keratitis, achromotrichia, retarded growth, and emaciation.
Based on: Sherry Lynn Sanderson, Nutritional Requirements and Related Diseases of Small Animals, Merck Manual, http://www.merckvetmanual.com/management-and-nutrition/nutrition-small-animals/nutritional-requirements-and-related-diseases-of-small-animals#v3328601 (12.07.2017)
