Dobermans and DCM Supplements
Diet and Heart Disease
Heart disease is common in dogs and cats, especially in older animals. As many as 10 percent of all dogs can have heart disease. Until the 1980s little was known of any relationship between diet and heart disease. Since then some important nutrients have been documented as important in preventing several forms of heart disease. Also as has been known for years, nutrition is important in managing fluid retention caused by chronic heart failure.
Taurine and Heart Disease
Animals manufacture the amino acid taurine that is essential for normal structure and function of the retina, platelets and heart. With taurine deficiency, cats can develop feline taurine-deficient dilated cardiomyopathy. The problem can be suspected from physical examination and thoracic radiographs showing heart enlargement. The problem is diagnosed by low plasma taurine (less that 20 micromol/L). Normal plasma taurine ranges between 50 and 120 micromol/L. Dilated cardiomyopathy also affects some American Cocker Spaniels which have low plasma levels of both taurine and L-carnithine (see below). Heart disease in other animals may be related to deficiency of these nutrients.
Most animals make enough taurine that deficiency doesn't develop. Cats cannot make enough to meet their needs, however. Cats depend on dietary taurine to supply adequate amounts. Diets containing animal proteins usually provide cats with enough taurine. There are some exceptions. Animal proteins in cheese and eggs contain little or no taurine. Cats cannot be fed these proteins unless they are supplemented with taurine. Plants also do not manufacture taurine so plant proteins in tofu or other soy products, beans, and cereals cannot be fed without added taurine supplements. Plant-produced proteins can be fed to dogs because they produce taurine from other amino acids. Taurine unlike other amino acids is not incorporated in protein structure but is free in body fluids. Meat processing that results in loss of its juices causes loss of taurine. Feeding processed nutrients can cause taurine deficiency in cats.
Feline taurine-deficient dilated cardiomyopathy was not recognized before cats were fed commercial pet foods. Cats living primarily on a carnivorous diet do not develop the problem; they consume enough taurine. Since the pet food industry recognized that taurine deficiency was a cause of medical problems, cat foods were supplemented with taurine. The first problem recognized was blindness caused by retinal degeneration. Addition of taurine to the diet solved that problem. Not enough taurine was added to prevent cardiomyopathies, however. With the recognition that heart problems were caused by taurine deficiency, more taurine was added to cat diets. Dry foods need high taurine, 1000 to 1200 mg taurine/kg dry weight. Canned foods need twice this amount to maintain normal taurine in body tissues. Cats with cardiomyopathy are treated with taurine, giving initial doses of 250 to 500 mg twice a day. If heart disease resolves, 6 to 12 weeks of therapy are required. (Other medications such as diuretics and vasodilators are also needed.) With improvement, taurine supplementation can be reduced to 250 mg daily. Recovered cats’ diets should always contain adequate taurine.
Despite awareness of problems caused by taurine deficiency, some cats may be fed inadequate taurine, especially if their diets contain primarily cereals or a single processed food. It is unknown if all commercial cat foods contain adequate taurine. All diets for feeding normal cats in website contain enough taurine. Vegetarian diets have taurine added in a powder or capsule form.
Carnitine and Heart Disease
Animals use lysine and methionine to synthesize L-carnitine. This compound is classified as a water-soluble vitamin or a nonessential amino acid. It is needed to transport free fatty acids into mitochondria of cardiac muscle. Carnitine is esterified with fatty acids to facilitate their movement across cell membranes. Inside mitochondria, oxidation of fatty acids generates energy in the form of ATP. Carnitine remaining after fat oxidation forms esters with potentially toxic waste products and transports them from mitochondria.
Carnitine deficiency is associated with heart problems in some Boxer, Doberman Pinscher and American Cocker Spaniel dogs with dilated cardiomyopathy. Some of these dogs improve and live longer with oral L-carnitine supplements. No one knows why some animals suffer from carnitine deficiency. It may result from inadequate dietary carnitine, lysine, or methionine or from intestinal malabsorption of these nutrients. Deficiency could also result from excess renal loss of these nutrients. Defective transport of carnitine esters across mitochondrial membranes could be a factor.
Carnitine deficiency is often difficult to diagnose. Dilated cardiomyopathy causes specific physical findings and radiographic changes. They do not prove carnitine deficiency, however. Plasma carnitine can be measured but that can be normal and not necessarily reflect carnitine levels in cardiac muscle. Up to 80 percent of dogs with carnitine deficiency in cardiac muscle have normal or increased plasma carnitine concentrations. Deficiency is proven only by measuring carnitine in cardiac muscle biopsies.Carnitine deficiency is treated with L-carnitine given orally at a dose of 2 grams mixed with food three times a day. This treatment appears to have few adverse side-effects. With success, appetite and activity improve after 1 to 4 weeks of therapy. Carnitine supplementation increases its level in heart muscle in most, but not all, dogs.Dilated cardiomyopathy caused by carnitine deficiency may be prevented by feeding diets high in carnitine. Carnitine is most abundant in red meat and dairy products. Feeding non-meat based commercial pet food results in dogs having plasma carnitine levels 50 percent lower than those consuming meat-based diets. Thus, although dogs are said not to be strictly carnivores and they can be fed vegetarian diets, feeding the cereal-based commercial dog foods is not likely to support adequate carnitine levels in heart muscle. Furthermore, heat may inactivate carnitine, something possible during processing of commercial dog food. Dilated cardiac myopathy caused by carnitine deficiency is prevented and treated best by feeding foods high in L-carnitine. The meat- and dairy product-based diets in this website provide dogs with abundant carnitine.