Pulmonary as well as aortic stenosis leads to cardiac murmurs, which can be perceived by the treating veterinarian by auscultation depending on the severity of the disease. However, the heart murmurs in an aortic stenosis do not correlate with the underlying severity of the disease, which is why further diagnostic procedures are always recommended.
For further clarification, an ECG, X-ray image and heart ultrasound are then performed.
As cardiac arrhythmias are relatively rare in proportion, an ECG often does not have the desired significance with regard to the presence of a heart disease. Often the resting frequency is increased and the excitation of the left ventricle is also shown as increased in the ECG. In addition, the relaxation phase of the left heart chamber can also be altered as a sign of the oxygen under-supply of the heart muscle occurring during this disease.
The X-ray image can provide first indications of the origin of the heart murmurs, but is often also not significant. In most cases the change in the affected artery itself can only be registered in extreme cases. Changes in the form of backlog symptoms in the abdomen respectively thorax or lungs are only visible in an advanced stage.
For precise diagnosis and grading of the severity, an ultrasound of the heart is the first choice. Depending on the severity of the disease, potential changes in the heart can already be visualized in a simple ultrasound image. By means of the Doppler ultrasound, the occurring turbulences and an increased blood flow velocity can also be shown and measured. An estimation of the severity can be made by measuring the blood flow velocity.
Depending on the exact findings and the respective symptoms of the affected dog, further diagnostic procedures, e.g. long-term ECG, blood pressure measurement as well as a haemogram should be performed.