2.4.2 Histological examination
Histological inspection of cardiac tissue should be performed by an experienced histopathologist. However, as histology of the equine heart is so seldom requested, interpretation of the findings is often based on general principles and experience in other species. Details of histological changes in valvular and myocardial disease are poorly documented.
If histology it to be performed, sections of atrial and ventricular myocardium, including the endocardium and epicardium, a section at the base of the mitral valve, a section including the region of the AV node and bundle of His, and any areas of obvious gross abnormality, should be taken. These should be placed into 10% formalin solution, but the pathologist should be consulted if any special stains are required because these sometimes require the use of other pre