The auscultation of heart sounds (monitoring with stethoscope) at the time of the "puppy check" is the first and most important screening method to detect congenital heart diseases. As written before, some congenital heart diseases are already manifested at the time of birth and can be detected with appropriate know-how and technological tools. A diagnosis at an early stage and therefore early treatment of such diseases strongly influence life quality and also lifetime of the affected animal. For these reasons it is important to have such a careful routine heart control at puppy age.
The most often diagnosed congenital heart diseases are the aortic stenosis, pulmonary valve stenosis, persistent ductus arteriosus botalli (PDA), ventricle partition defect, mitral valve dysplasia und tricuspid valve dysplasia, as well as atrial septum defects. All these congenital heart diseases can be detected as heart murmurs during auscultation except for the atrial septum defect, which is not detectable for the human ear. Furthermore the auscultation only tells the presence of a finding but it is not possible to make a diagnosis (including exact location and degree of severity).
"Not every heart murmur implies a cardiac defect.
Not every heart disease causes a heart murmur."
These limitations underline the importance of a heart ultrasound examination, which is the best choice for heart checkups – easy and precisely!
ECG monitoring and x-rays can support the diagnosis, but do not provide an exact result (especially for puppies), as symptoms like stagnant effects or rhythm disturbances develop over time and are not unique for a special heart disease.
The 2-dimensional heart ultrasound can visually show the myocardium (heart muscle), the heart valves as well as their movements. Doppler ultrasound can additionally show the blood flow in quantity and quality, whereby there is difference between colour Doppler and spectral Doppler. Colour Doppler shows the turbulences which are responsible for the heart murmurs in colour and thus the localization of the defect is recognizable. By means of spectral Doppler ultrasound it is possible to measure the additional pressure via flow velocity on the ill area and to define the degree of severity of the illness.
If the heart disease of a dog is in a progressed state on the first check-up, and maybe symptomatically intense, the examination starts for an experienced(!) cardiologist with his first impression of the dog. For a specialist it is possible to make a first presumed diagnosis on the basis of case examples of everyday practice via the external appearance and additional information like breed and age of the animal, which will be proved later-on with the introduced examination methods.