Heart disease is very common in dogs. Most cases of heart disease in dogs are hereditary, rather than acquired. This means that, unlike in humans, obesity and a sedentary lifestyle are not major causes of heart disease in dogs (although obesity exacerbates heart disease in all species).
There are two major forms of heart disease in dogs. Small breeds are prone to valve disease. Valve disease causes the blood to flow incorrectly through the heart and lungs. Large breeds are prone to cardiomyopathy, a syndrome in which the muscles of the heart lose the ability to function normally. Either condition can lead to heart failure and death.
The mainstays of diagnosing canine heart disease have been physical exam, evaluation for irregular heart sounds known as murmurs, X-rays and echocardiography (ultrasound of the heart). Echocardiography is especially effective at diagnosing heart problems. However, in many cases the problem is not detected until it has been present for a very long time. And, as with all medical conditions, treatment for canine heart disease is most effective if the problem is detected early.
Fortunately, a paper in the May 15, 2008 Journal of the American Veterinary Medical Association describes a new test that may soon become available to identify dogs with heart disease. The test would be a blood test that could be performed routinely on at-risk breeds.
The test would involve measuring the level of a peptide (a very small protein) in the blood. A recent study demonstrated that blood levels of the peptide reliably predict the presence and severity of heart disease in dogs.
It may be several years before any test involving the peptide is available for veterinarians. However, it is encouraging to know that in the future it may be possible to diagnose heart disease earlier and more easily in our canine friends.
The paper discussed in this post is Oyama, et al J Am Vet Med Assoc 2008;232:1496-1503
Image credit: Heikenwaelder Hugo. Image licensing information: CC
Image confession: it is a human heart. But the canine heart is anatomically similar.