I generally recommend that my clients disregard supplements and focus on feeding their dogs an appropriate amount of a well-balanced, high-quality dog food. Adding supplements to an already nutritionally complete diet for a healthy adult dog or puppy can actually do more harm than good.
There are times, however, when I must recommend otherwise. For instance, when I am faced with a Newfoundland, Cocker Spaniel, or Boxer with a type of heart disease called dilated cardiomyopathy (DCM).
Dilated cardiomyopathy is a disease of the heart muscle. The disease causes the part of the heart (the left ventricle) responsible for pumping blood that has returned from the lungs throughout the body to become too weak to adequately perform this function. Less commonly, the right ventricle that receives blood from the body and pumps it to the lungs is affected either in addition to or instead of the left ventricle.
The symptoms of dilated cardiomyopathy can include weakness, exercise intolerance, coughing, difficulty breathing, and if the right ventricle is affected, a fluid-distended abdomen.
DCM is primarily a genetic disease. Doberman Pinschers, Great Danes, Boxers, Newfoundlands, Portuguese Water Dogs, Dalmatians, and Cocker Spaniels are at the highest risk for DCM, but the disease can affect any breed, even mutts.
In some cases, a nutritional deficiency can cause dilated cardiomyopathy. The amino acid taurine plays a role in the proper development and function of the heart muscle. Dogs can make taurine from cysteine and methionine, so as long as they eat a diet that supplies sufficient amounts of these amino acids and/or taurine directly, taurine deficiency should not be a problem. However, research suggests that some Newfoundlands and Cocker Spaniels have altered taurine metabolism, and dilated cardiomyopathy caused by taurine deficiency can develop even when one of these individuals is on a diet containing amounts of cysteine, methionine, and/or taurine that are generally recognized to be adequate.
Boxers present another unique scenario. L-carnitine is an amino acid that is necessary for heart muscle cells to make the energy needed for them to contract. One study has shown that a deficiency of L-carnitine in Boxers may play a role in the development of some cases of DCM in this breed.
What does this mean for owners? If you have a Newfoundland or Cocker Spaniel that is diagnosed with dilated cardiomyopathy, taurine supplements should be part of the treatment protocol. The same can be said for Boxers and L-carnitine. Supplementation is not helpful in all cases, but it certainly doesn’t hurt to try.
This begs the question: Should healthy Newfoundlands, Cocker Spaniels and Boxers receive taurine or L-carnitine supplements? In most cases this is not necessary, but if you are a "better safe than sorry" type of person, doing so might bring you some peace of mind. Taurine and L-carnitine supplements are relatively inexpensive and if they are not needed by the dog’s body, they will be broken down and excreted as waste, which should not be harmful as long as the dog’s kidneys are functioning well.
Talk to your veterinarian about which foods and supplements might be appropriate for your dog.
Dr. Jennifer Coates