heart problems
Heart disease is seen in all dogs, pure breed and mixed bred. We have a small incidence of heart problems in this breed. We will outline briefly, different conditions, how they are inherited, and links to articles which elaborate on them more completely.
Echocardiogram of a dog's heart
[image: heartsmart.vet.tufts.edu]
Heart Murmur
is a term used to describe a “sound” that the heart makes in the process of pumping blood. All of the below conditions can cause “Heart Murmurs”. When a murmur is heard, further testing is required to determine it’s underlying cause. While some murmurs in puppies are innocent and might disappear, only growth and time can determine this. Adult onset murmurs should always be followed up with testing and possible treatment.
Patent Ductus Arteriosus (PDA)
occurs when the ductus arteriosus-a vessel in the unborn fetus that allows blood to bypass the lungs remains open after birth. The result is a leak from the aorta through the open ductus into the right side of the heart, causing the left ventricle to work harder to maintain adequate blood flow. Inheritance is complex.
Sub-Aortic Stenosis
is also known as sub-valvular aortic stenosis, is a narrowing of the connection between left ventricle and the aortic artery. This increases the resistance to blood flow from the left ventricle out to the body. This is a polygenic dominant disease, although some of the data might vary among different breeds.
Pulmonic Stenosis
which usually affects small breeds, is a narrowing of the connection between the right ventricle and the pulmonary artery, increasing the resistance to blood flow and making it more difficult for the right ventricle to pump blod through the lungs. Pulmonic stenosis appears to be a polygenic threshold trait.
Valvular Disease
While any of the valves in the heart can be diseased, we will discuss the most commonly seen problem here. Pulmonic Stenosis, which usually affects small breeds, is a narrowing of the connection between the right ventricle and the pulmonary artery, increasing the resistance to blood flow and making it more difficult for the right ventricle to pump blood through the lungs. Pulmonic stenosis appears to be a polygenic threshold trait
Mitral Valve Dysplasia
is a condition where the leaves of the Mitral Valve are deformed, are present at birth, and can allow blood to leak backwards,decreasing blood flow through the heart. The amount of deformity of the valve, will dictate the size of the leak, and further complications. A mild deformity, might not produce a murmur, while more severe deformities with large leaks will and at a young age. Inheritance is complex and unknown at this time.
Mitral Valve Degeneration
is the most common cause of Congestive Heart Failure of all elderly dogs. It appears to be more prevalent in small to moderate size breeds, and more often seen in the male. The age of onset is of most importance in the medical prognosis for the individual dog. Inheritance is complex and different with different breeds.
The ACVIM recommends a referral to a cardiologist for diagnosis, and treatment for any cardiac condition. Screening evaluations are done by OFA and ARCH registries. Clinics are offered for screenings by both these these registries. Clinic information can be located on their web sites. Each of these registries have their own guidelines for screening, and inclusion in to their registries.