What is carnitine?
Carnitine (L-carnitine is the active form of carnitine) is an amino acid that the body uses to turn fat into energy. Carnitine is not normally considered an essential nutrient because the body can manufacture all it needs in the liver using the amino acids lysine or methionine, and vitamins C, B1 and B6. However, carnitine is found in high levels in red meat and dairy products.
"Carnitine is not normally considered an essential nutrient because the body can manufacture all it needs..."
Carnitine is required for transporting long chain fatty acids and their derivatives into the mitochondria of cells. Once transported into the mitochondria, which are tiny little powerhouses present in each cell, the fatty acids are converted into the ultimate chemical energy source of the body, known as ATP. Mitochondria are abundant in the cells of all organs that have a large energy requirement, including the heart, kidney, skeletal muscle, liver, and testis.
Why recommend administration of carnitine to my pet?
The main indication for carnitine supplementation is for the pet with heart disease, specifically dilated cardiomyopathy in dogs. Although the liver can usually manufacture all the carnitine required under normal conditions, it may be useful as a supplement to debilitated heart muscle that needs all the help it can get. There is no reason to suspect that it may not prove useful in the management of other small animal cardiac disorders, given its wide use in humans.
Sperm cells also have high-energy requirements, and carnitine supplementation has been shown to improve sperm motility and numbers in infertile men.
Because carnitine facilitates the metabolism of fatty acids and their derivatives, it has shown promise in the treatment of ketoacidosis (a serious metabolic consequence of uncontrolled diabetes) and hyperlipidemia (elevated levels of fat in the bloodstream). It also appears beneficial in the management of both obesity and fatty liver syndrome in cats. Simultaneous choline administration is required for the uptake of carnitine into liver cells.
One other chemical in the human body derived from carnitine is L-acetylcarnitine, which acts as a neurotransmitter (a chemical that helps nerve impulse transmission) in the brain. Significant improvement has been noted in humans with memory loss and with Down's syndrome when carnitine was supplied as a supplement. It may likewise prove beneficial in the treatment of cognitive dysfunction in small animals.
How much experience is there with the use of carnitine in pets?
Carnitine has been used successfully to help some dogs with dilated cardiomyopathy. A true carnitine deficiency may exist in a small number of dogs, as suggested by studies published in the 1990's showed that carnitine supplementation was beneficial in the treatment of cardiomyopathy in both American Cocker Spaniels and Boxers. Thus, in these breeds, supplementation with L-carnitine may be especially useful.
What species of animals are being treated regularly with carnitine?
Carnitine should be considered as a supplement for the treatment of obesity, cardiomyopathy, hyperlipidemia and diabetic ketoacidosis, which are conditions found in both dogs and cats. It appears to be effective for the treatment of fatty liver syndrome in cats when administered with choline.
How much research has been conducted on this supplement?
Carnitine is one of our better-researched supplements and appears to be of benefit in dogs with dilated cardiomyopathy and cats with obesity, ketosis, and fatty liver syndrome.
How successful is supplementation with carnitine?
For some dogs with true carnitine deficiency, supplementation can be life saving. For most pets with heart disease, hyperlipidemia, fatty liver syndrome, and ketoacidosis, carnitine supplementation should be used as part of an integrated treatment that includes other nutraceuticals and conventional treatments. Since L-carnitine is the active form of carnitine, this form of carnitine should be used as a supplement.
How safe is carnitine?
L-carnitine is very safe, simply because it is already a crucial constituent of almost every cell in our bodies. It is consumed whenever meat and dairy products are eaten. People are advised not to use other forms of carnitine, particularly D,L-carnitine, which reduces L-carnitine levels of skeletal and heart muscle, leading to muscle pain and decreased exercise tolerance.
"Pets that are taking anticonvulsants, particularly phenytoin (Dilantin) or phenobarbital, may need extra carnitine..."
The maximum safe dosages for young children, pregnant or nursing women, or those with severe liver or kidney disease have not been established. High doses may cause diarrhea and heartburn in humans. Pets that are taking anticonvulsants, particularly phenytoin (Dilantin) or phenobarbital, may need extra carnitine, especially those with heart disease.
Where do I obtain carnitine and do I need a prescription?
Consumers are advised that quality of supplements may vary significantly among manufacturers. Your veterinarian may have preferred supplement manufacturers that he or she will recommend. Carnitine is available over-the-counter, and is often combined with other supplements that also improve energy production in the mitochondria, such as coenzyme Q10 and taurine. When used to treat fatty liver syndrome in cats, it should be administered with choline.