You might be familiar with L-carnitine as a supplement popular among bodybuilders. But did you know it can also be useful for your animal’s health? This nutrient plays a vital role in energy production for muscle cells and may be helpful for treating a wide variety of conditions.
Amino acid combo
L-carnitine is composed of the amino acids lysine and methionine. It is naturally produced by the liver and kidneys, then stored in skeletal muscle, heart and brain tissues. While it can be readily absorbed from food, most healthy people and animals are capable of synthesizing adequate amounts in their bodies.
L-carnitine plays an important role in fat metabolism. It assists with the transport of fatty acids from the cytosol (intracellular fluid of the cell) into the mitochondria (the cell’s energy factory). This allows the cell to utilize the fat for energy production, which is especially useful for brain and heart function as well as muscle movement. Research has shown that L-carnitine improves the function of myocardial cells (the cells that make the heart contract) and acts as an antioxidant. It scavenges free radicals, which can damage cells and DNA.
What happens when there isn’t enough?
A deficiency in L-carnitine is generally diagnosed in adult dogs and is characterized by cardiomyopathy (abnormal heart muscle, dilated being the most common). Several breeds have been shown to have a predisposition to dilated cardiomyopathy, and include the boxer, Doberman pinscher, great Dane and other giant breeds.
A diagnosis of L-carnitine deficiency can be made through a biopsy of the affected tissue (heart). This is not commonly done, however, so this is a rare diagnosis in dogs. Since there is no routine screening done for L-carnitine deficiency, it is unclear how prevalent the condition is. In people, symptoms occur when the deficiency is 10% to 20% below normal levels, so there could be many dogs with mild deficiencies that go undiagnosed.
When should you consider supplementation?
Growing evidence points to the potential benefits of supplementation with L-carnitine.
1. In dogs, it is most frequently recommended for heart disease. Studies have shown improvements in the cardiac function of cocker spaniels and boxers with dilated cardiomyopathy, though the results are not as consistent for other breeds with the same condition.
2. L-carnitine may also be helpful in the prevention and treatment of diabetes in both dogs and cats. This may be due to its action as an aid in fat metabolism, which may make it useful in weight loss and obesity management. There is some evidence that L-carnitine can accelerate weight loss in obese cats.
3. Another potential use is for cases of myopathy (muscle weakness), since L-carnitine may be helpful for building muscle mass in people. There is one published report of a border collie successfully treated with L-carnitine, CoQ10 and vitamin B for a rare myopathy condition that caused weakness in his hind legs.
4. One study demonstrated that L-carnitine slows cognitive decline in dogs. Beagles supplemented for two months with L-carnitine and alpha-lipoic acid showed improved learning and discrimination compared with beagles that received no supplement.
Sources of L-carnitine
As always, the best method of supplementation is to feed your companion good quality food. Sources high in L-carnitine include red meat (especially lamb), fish, poultry, tempeh, and peanut butter.
If additional supplementation is needed, there are many options on the market to choose from. Manufacturers are responsible for following minimum quality standards, labeling their products appropriately and ensuring there are no contaminants present. Therefore, it is up to you to be a wise shopper and to do your homework and/or consult an integrative or holistic vet before choosing a product.
As with any supplement, L-carnitine is not a cure-all. But it is very safe, and may prove beneficial for a range of health issues in both dogs and cats.
Are there any contraindications?
L-carnitine is generally very safe, though there are a few instances in humans when caution is warranted. On the veterinary side, there are no documented instances of side effects from supplementation with L-carnitine.
However, because of its ability to antagonize peripheral thyroxine receptors, L-carnitine should probably not be given to hypothyroid dogs. If you feel your dog will still benefit from supplementation, and he is on thyroid medication, consult with your veterinarian before starting L-carnitine, since it may alter the dose of his medication.