Congenital sternal cleft in a DSH cat: A case report

The sternum, essential for protecting intrathoracic structures and enabling thoracic stability and breathing motion, is a vital part of small animal thoracic anatomy. Evaluating the sternum is crucial in small animal practice, with typical anatomy including eight to nine sternebrae and species-specific variations. Congenital sternal anomalies, such as pectus excavatum, pectus carinatum, and sternal cleft, though rare, can have significant clinical implications. Sternal cleft, characterized by incomplete fusion of sternebrae, is particularly uncommon in veterinary literature, with limited documented cases. A 2-year-old neutered male domestic shorthair cat, presenting with vomiting and anorexia, underwent comprehensive diagnostic workup at the Small Animal Veterinary Hospital. Laboratory tests indicated leukocytosis and renal dysfunction. Imaging revealed enlarged kidneys, dilation of the urinary system, mild bronchointerstitial lung patterns, and a unique sternal structure. CT and 3D reconstruction confirmed a complete "U"-shaped sternal cleft involving all sternebrae except manubrium process and seventh sternebra. Supportive treatment was administered, but the cat succumbed to systemic complications. Congenital sternal abnormalities in small animals, including sternal cleft, are rare and often associated with other thoracic or abdominal defects. This case highlights the complexity of diagnosing and managing such anomalies, emphasizing the importance of imaging for accurate assessment. This report of a complete "U"-shaped sternal cleft in a cat without respiratory symptoms underscores the necessity of documenting congenital anomalies. Comprehensive diagnostic imaging and multidisciplinary management are crucial for improving outcomes in similar cases. Despite the rarity of sternal cleft, reporting these cases enhances understanding and informs clinical decision-making.