| Abstract: | Measurements of the heart and thorax were made on lateral and ventrodorsal thoracic radiographs of normal cats. The degree of correlation between selected cardiac and thoracic measurements was determined. Absolute measurements and ratios of measurements in normal cats and in cats with certain cardiac diseases were compared and their diagnostic value was evaluated. It was concluded that on the lateral thoracic radiograph the ratio of the cranio-caudal width of the heart to the distance between the cranial border of the fifth rib and the caudal border of the seventh rib was a highly reliable indicator of cardiac enlargement. On the ventro-dorsal radiograph the ratio of the maxium width of heart to the width of the thorax at the same level was the best indicator of increases in cardiac size. |
