heart disease

Heart problems are relatively common in dogs and cats. A range of supplements can help support your cardiac patients, and make an effective addition to your treatment plan.

The most common types of heart or heart-related disease in cats are hypertrophic cardiomyopathy (HCM), dilated cardiomyopathy (DCM), hypertension, and chronic heart failure (CHF). In dogs, we most often see chronic valvular disease, DCM, heartworm, and primary arrhythmias. This article provides an overview of cardiac-supportive supplements for dogs and cats. Note that some of these heart problems are breed-related, so response to supplements can also be breed-related.


This is probably the most important supplement for the prevention and treatment of heart disease. Its importance for cats in particular has prompted AAFCO to increase the recommended amounts of taurine in cat food. However, we still see cases of feline heart disease which are responsive to taurine. A recent in-depth nutritional analysis of 26 commercial plant-based diets found that none met the minimum nutritional standards recommended by AAFCO and FEDIAC. Taurine was the most common under-supplied nutrient. Crude protein in most of these diets was above the recommended minimum, projecting a false idea of their nutritional adequacy. Homemade diets were also found to be problematic for taurine content.

Dogs can also have taurine-responsive cardiac problems, which are especially prominent in certain breeds, most commonly the Golden Retriever, American Cocker Spaniel, and Newfoundland. This would suggest that recommendations for taurine levels are too low for canine as well as feline diets. Unlike cats, dogs can manufacture their own taurine, but this mechanism most likely works best for dogs on a meat-based diet, not those on a low-quality commercial diet. Dogs such as the Golden Retriever, which have a higher-than-average chance of developing taurine-responsive DCM, have probably lost some of this capacity, compared to their wild relatives.

A retrospective study of dogs with DCM, which included 56 dogs on grain-free diets, showed that subsequent supple-mentation of taurine helped the dogs in the grain-free group live significantly longer (up to 455 days longer) than those that stayed on the same diet with no supplementation.

ACVIM guidelines for the use of taurine in canines and felines with non-DCM heart disease in general are positive, but conservative. They recommend measuring plasma taurine concentrations and only supplementing when plasma concentrations are low or animals are in later stages of heart disease. Taurine does not easily diffuse from within a cell to plasma. So plasma concentrations of taurine do not immediately reflect intracellular levels. Because of the number of cardiac problems that are responsive to taurine, it would be more prudent to initiate taurine supplementation whenever a heart abnormality is detected, even if the dog or cat is not yet exhibiting clinical signs.

Recommended dose: For cats, dosage varies from 125 mg per day (for growth and maintenance) to 250 mg q 12 hr for cardiomyopathy (as high as 500 mg bid with B6 for epilepsy). For dogs with DCM, one recommended dose is 500 mg bid, accompanied by 1,000 mg l-carnitine bid. A second recommendation is 20.6 mg/kg PO q 12 hr (375mg per 40 lb). Taurine is palatable and non-toxic, and the contents of a taurine capsule can be poured onto a pet’s food — even for cats.


This supplement does not have as much published research behind it, but cardiologists and many veterinarians recommend its use in heart disease, along with taurine. L-carnitine is crucial for transporting fatty acids across the membrane of mitochondria for use in ATP production. L-carnitine improves exercise endurance in human heart patients. A retrospective study of Chinese human cardiac patients who were given l-carnitine as a supplement showed improved symptoms for heart disease and increased survival times. Some veterinary researchers mentioned cost as a negative factor, but the cost of 500 mg of l-carnitine is just three times as much as the very low cost of 500 mg of taurine. L-carnitine is well within the limits of what pet owners are able to pay.

Recommended dose: 1,000 mg to 2,000 mg twice a day.


Arginine is the immediate precursor for nitric oxide, a vasodilator. It can reduce injury from hypoxic conditions and increase vasodilation, which can benefit the heart and decrease blood pressure.

Recommended dose:760 mg/100 kcal.OMEGA-3


The American Heart Association (AHA) recommends just one supplement for human individuals with coronary heart disease: Omega-3-fatty acids.

Eicosapentanoic acid and docosahexaenoic acid (EPA and DHA) found in fish body oil have a beneficial effect one echocardiographic measurements and cardiac biomarkers in cats with HCM. Fish oil decreases arrhythmias and the potential for arrhythmias. It increases survival time in dogs with chronic heart disease, and improves cardiac cachexia. Molecularly distilled fish oil can help decrease the amount of environmental contamination. Another way to accomplish the same thing is by using algae-derived EPA and DHA.

Recommended dose: 300 mg combined DHA and EPA per 10 pounds body weight per day.COQ10Also known as coenzyme Q10 or ubiquinol, this supplement has not received enough attention in the veterinary world. It has shown benefits for ischemic heart disease in humans.

CoQ10 plays an essential part in ATP production, as an electron carrier in the mitochondrial respiratory chain. Without it, oxidative phosphorylation could not occur

CoQ10 production in the body declines as we age, partly explaining the declining energy levels in elderly pets. It also acts as a lipid-soluble antioxidant, and can repress expression of pro-inflammatory genes. It helps improve cardiovascular health, increase energy levels, and lower blood pressure. ACVIM recommends its use in dogs with mitochondrial myopathy. In view of its role in ATP production, and the lower concentrations in older animals, it would be wise to use it in any older pet with heart disease. Recommended dose:100 mg once a day.


Vitamin E requirements rise with an increase in polyunsaturated fatty acids. It has an anti-inflammatory effect and reduces oxidative stress, and has been shown to be beneficial in human heart disease. Decreased levels of vitamin E are found in both dogs and cats with DCM. Cats with hypertrophic cardiomyopathy exhibit increased oxidative stress markers, and some cardiologists recommend that antioxidants be added to the treatment regimen for this disease. The natural d-alpha form is preferred to the dl-alpha form, since the latter has only42% of the activity of the d form.

Recommended dose: 5 IU d-alpha tocopherol per pound body weight. This can be added to the food as a gel cap or oil.


  • Vitamin C is another antioxidant, and is generally useful for cardiac disease, especially as it progresses. When vitamin E acts as an antioxidant, it is transformed into its pro-oxidant form. VitaminC is the cofactor that cycles vitamin E back into its antioxidant form. In any condition involving increased oxidative stress, when vitamin E is given, vitamin C should also be included.
  • B vitamins may be depleted when animals are given diuretics. Riboflavin or thiamine given at a dose of 100 mg once a day can be helpful with mitochondrial myopathy.
  • Magnesium is the most important mineral for the cardiac patient. It can help with canine arrhythmias, and when heart failure progresses
  • Dogs with cardiac disease may suffer from hypomagnesemia, and magnesium levels should be included in their lab tests. Magnesium should always be added for any dog with low magnesium blood levels. One study of supplements for heart disease added magnesium to a supplement mix regardless of blood status.

Magnesium is a coenzyme for sodium-potassium ATPase and serves as a cofactor for hundreds of enzymatic reactions. It plays a big part in calcium reactions, modulating its release from sarcoplasmic reticulum. It also decreases the excitability of nerve and muscle membranes, and can help reduce high blood pressure. The level of magnesium in critical care diets and total parenteral nutrition formulas is low and not sufficient to treat hypomagnesemia.

Magnesium chloride, magnesium gluconate, magnesium oxide, or magnesium hydroxide can be given at1-2 mEq/kg PO q 24 hrs. Magnesium must be used with caution in patients with renal insufficiency. The recommendation is to decrease the recommended dose by 50%.

  • Potassium supplementation should not be required unless the patient is on diuretics. Serum potassium may be low in such a case, but this most commonly occurs when using torsemide. Hyperkalemia may also be seen with heart disease, but this is rare in patients being treated with diuretics. The only time supplemental potassium should be given is when hypokalemia is present, confirmed by laboratory analysis.


Less research has been done on cardiac supplements for dogs with chronic valvular disease than in dogs or cats with DCM or HCM. In one study, dogs with early chronic valvular disease with clinical signs were given a diet that included Omega-3 fatty acids, vitamins C and E, arginine, taurine, and carnitine. They showed significant measurable improvement after four weeks. The internal diameter of both the left atrium and left ventricle decreased, and mitral valve regurgitation was reduced.

Another study of dogs with early preclinical mitral valve disease involved feeding them a diet enriched with MCT oil, fish oil, fish meal, l-lysine, dl-methionine, taurine, magnesium sulfate, and additional dl-alpha tocopherol. The diet reduced left atrial enlargement in these dogs.

Supplements beneficial for cardiac patients

  • COQ10


These trials along with previous research show the benefits of using multiple supplements rather than a single one. Because these supplements work in different ways to benefit the heart, it makes sense that the more that can be added without danger of toxicity, the better the effects. Taurine and vitamin E are two palatable supplements with beneficial effects that can be added to food without causing rejection because of the taste.

The AKC also recommends several supplements, including Omega-3 fatty acids, CoQ10 and antioxidants, so clients who follow them may ask you about those three. Familiarity with these and the other supplements highlighted in this article will help increase client confidence in the recommendations you make.



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