Morphology of subclavian artery branching patterns in cats (Felis catus)

Importance: The subclavian artery (SB) is a crucial vascular structure that supplies the neck, thoracic wall, and forelimb. In carnivores, SB branching patterns exhibit considerable interspecific and intraspecific variation. Despite the increasing recognition of cats as companion animals, detailed studies of feline SB branching patterns remain limited. Objective: We aimed to investigate the SB branching patterns in cats, analyze intraspecific variations, and compare these findings with those observed in other carnivores. Methods: Silicone casts of the SBs were prepared from 35 cats (15 males and 20 females). Branching locations of arterial branches were measured as the distance from the aortic arch to each branching point. The SB branching patterns were analyzed based on the branching relationships among the four major branches: the vertebral artery (VT), costocervical trunk (CCT), superficial cervical artery (SC), and internal thoracic artery (IT). Results: Various branching patterns were observed in the SB with a total of 33 branching types. The main branching patterns were determined to be VT, followed by IT, CCT, and SC. The right SB branches exhibited more distal branching locations from the aortic arch compared to the left SB branches. Across individuals, the VT, CCT, and SC followed a consistent order, whereas the IT varied in position. Conclusions and Relevance: This study offers a detailed analysis of the SB branching patterns in cats, highlighting significant intraspecific variation and distinctive branching order. These findings enhance our understanding of vascular diversity among carnivores and provide a strong foundation for future comparative anatomical and developmental investigations.