New branching patterns of the subclavian arteries found in Thai native dogs

• Main Authors: Rachanchai Chawangwongsanukun, Damri Darawiroj, Tuempong Wongtawan, ราชันชัย ฉวางวงศานุกูล, ดำริ ดาราวิโรจน์, เติมพงศ์ วงศ์ตะวัน
• Other Authors: Mahidol University. Faculty of Veterinary Science. Department of Preclinic and Applied Animal Science
• Format: Article
• Language: English
• Published: 2020
• Subjects: Anatomical variation; Subclavian artery; Thai native dogs; ความหลากหลายทางกายวิภาคศาสตร์; สุนัขไทยพื้นบ้าน; Journal of Applied Animal Science
• Online Access: https://repository.li.mahidol.ac.th/handle/123456789/60652
• Institution: Mahidol University

The majority of dogs in Thailand are Thai native dogs, but their anatomy is rarely recorded. In this study, we aimed to investigate the anatomical variation of subclavian arteries of dogs in Thailand. We observed 43 cadavers of Thai native dogs compared to 15 cadavers of other breeds during teaching veterinary anatomy. Four new branching patterns of subclavian arteries were found and named as type Va, Vb/Vd, VIb, and VIIb/ VIId. Type V had had vertebral artery as the first branch, then costocervical and superficial cervical arteries arose together. Type Vb/Vd, the internal thoracic artery arose opposite either to the costocervical trunk or the superficial cervical artery while type Va the internal thoracic artery arose after the superficial cervical artery, but not opposite to the costocervical trunk. VIIb/VIId was described as vertebral artery is the first branch and then common trunk of costocervical and superficial cervical arteries, the internal thoracic artery arose opposite either to the costocervical trunk or the superficial cervical artery. These new patterns accounted for 5.9% of Thai native dogs in this study. From the new patterns, we created the new model that cover all possible branching patterns of the subclavian artery (26 variations). Notably, the highest frequency of branching patterns in Thai native dogs was type I (60.5%), specifically type Ib (33.7%), which was also the major pattern for both sides of subclavian arteries and both sexes of dogs. Type Ib was described as the vertebral artery was the first branch, then the costocervical trunk, later the superficial cervical and the internal thoracic arteries arose oppositely. This knowledge is useful for veterinary anatomical education, physiology, imaging diagnosis, and the surgical treatment for canine thorax, particularly in Thai dogs.