Abstract: Three cats had shortness of breath after different surgeries. In order to diagnose and treat their disease, general clinical examination, blood cell classification and count, blood biochemical index, X-ray, and cardiac ultrasonography examination were taken, and the treatment was carried out according to the results. The results showed that all three cats had myocardial hypertrophy and left atrial dilation, and the initial diagnosis was hypertrophic cardiomyopathy（HCM） or transient myocardial hypertrophy（TMT）; at the same time, all three cats were accompanied by different degrees of cardiogenic pulmonary edema. Symptomatic relief can be obtained with oxygen and diuretic therapy, and subsequently managed with HCM regimen. In the subsequent echocardiography, the cardiac structure and function of the three cats returned to normal, and the prognosis was good. Three cats were eventually diagnosed with TMT.This suggested that TMT should be included in the differential diagnosis when a young cat was diagnosed with an HCM phenotype of congestive heart failure following a cat-stress prodromal history.