Deformations of the Cervical and Cranial Thoracic Vertebrae in a Bedridden Asian Elephant

Gunji, Megu; Takai, Akira; Endo, Hideki

doi:10.5686/jjzwm.19.79

Cited by 2 publications

(3 citation statements)

References 8 publications

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“…A large number of pathologies described above can be associated with the effects of keeping most of the studied animals in captivity, lack of activity, and age‐related changes (Gunji et al, 2014; O'Regan & Kitchener, 2005). However, most of the artiodactyls we studied earlier (Belyaev et al, 2021b) were animals kept in captivity as well, but they were characterized by a notably smaller number of fusions between vertebrae with complete loss of mobility (7 of 30 specimens in perissodactyls, 3 of 54 specimens in artiodactyls).…”

Section: Resultsmentioning

confidence: 99%

Truly dorsostable runners: Vertebral mobility in rhinoceroses, tapirs, and horses

2022

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The vertebral column is a hallmark of vertebrates; it is the structural basis of their body and the locomotor apparatus in particular. Locomotion of any vertebrate animal in its typical habitat is directly associated with functional adaptations of its vertebrae. This study is the first large‐scale analysis of mobility throughout the presacral region of the vertebral column covering a majority of extant odd‐toed ungulates from 6 genera and 15 species. In this study, we used a previously developed osteometry‐based method to calculate available range of motion. We quantified all three directions of intervertebral mobility: sagittal bending (SB), lateral bending (LB), and axial rotation (AR). The cervical region in perissodactyls was found to be the most mobile region of the presacral vertebral column in LB and SB. Rhinoceroses and tapirs are characterized by the least mobile necks in SB among odd‐toed and even‐toed ungulates. Equidae are characterized by very mobile necks, especially in LB. The first intrathoracic joint (T1–T2) in Equidae and Tapiridae is characterized by significantly increased mobility in the sagittal plane compared to the typical thoracic joints and is only slightly less mobile than typical cervical joints. The thoracolumbar part of the vertebral column in odd‐toed ungulates is very stiff. Perissodactyls are characterized by frequent fusions of vertebrae with each other with complete loss of mobility. The posterior half of the thoracic region in perissodactyls is characterized by especially stiff intervertebral joints in the SB direction. This is probably associated with hindgut fermentation in perissodactyls: the sagittal stiffness of the posterior thoracic region of the vertebral column is able to passively support the hindgut heavily loaded with roughage. Horses are known as a prime example of a dorsostable galloper among mammals. However, based on SB in the lumbosacral part of the backbone, equids appear to be the least dorsostable among extant perissodactyls; the cumulative SB in equids and tapirs is as low as in the largest representatives of artiodactyls, while in Rhinocerotidae it is even lower representing the minimum across all odd‐toed and even‐toed ungulates. Morphological features of small Paleogene ancestors of rhinoceroses and equids indicate that dorsostability is a derived feature of perissodactyls and evolved convergently in the three extant families.

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Section: Resultsmentioning

confidence: 99%

Truly dorsostable runners: Vertebral mobility in rhinoceroses, tapirs, and horses

2022

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“…To diagnose this calf, a CT scan of the neck and thorax was performed and these cases were observed: articular facets of the cervical and first three thoracic vertebrae possessed intricately rough surfaces and the anterior articular processes of C4, C5 and C6 intruded to the adjacent processes. This study concludes that a long-term lying posture under the bedridden condition might cause the over-dorsalisation of the neck and the deformations of the articular processes in large mammals (Gunji et al, 2014). Marchant and Shoshani (2007) studied the head muscles of Loxodonta africana and Elephas Maximus and also studied their anatomical differences.…”

Section: Introductionmentioning

confidence: 82%

“…Gunji et al. (2014) report an abnormality of the neck in a bedridden Asian elephant. To diagnose this calf, a CT scan of the neck and thorax was performed and these cases were observed: articular facets of the cervical and first three thoracic vertebrae possessed intricately rough surfaces and the anterior articular processes of C4, C5 and C6 intruded to the adjacent processes.…”

Section: Introductionmentioning

confidence: 99%

CT anatomy of cervical vertebrae of Asian elephant (Elephas maximus)

Zehtabvar

Vajhi

Akbarein

et al. 2022

Veterinary Medicine & Sci

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Background Elephants are currently the largest mammals on earth. A comprehensive examination of the anatomy of this animal to diagnose various disorders is required. In addition, due to the heavy head of these animals, adaptations have been made in the anatomical structure of the neck that is worth studying. Objective This study aimed to investigate a standard morphologic and morphometric description of the elephant cervical spine. Another aim of this study was to compare the changes in the cervical skeleton of elephants with horses and cattle. Methods For this study, the cervical vertebrae of the Asian elephant, cattle and horse were examined. CT Images were obtained using Somatom Spirit II CT Machine. Statistical analysis was done by SPSS 24 software. Results Two dorsal tubercles and a groove between them were observed on the dorsal arch of the atlas vertebra of the Asian elephant. In elephant samples, the variation of vertebral body height, spinous process height, transverse process width, vertebral body length and vertebral foramen volume indices were statistically significant. The volume of the vertebral foramen in the elephant decreases in the second vertebra compared to the first vertebra, decreases in the third vertebra, decreases in the fourth, increases in the fifth, decreases in the sixth and increases in the seventh. Conclusions In this study, the structure of the cervical vertebrae of the Asian elephant was examined, and certain features were observed. One of the main features was the reduction of the length of the vertebrae, which leads to the decrease of the ratio of neck length to the size of the body. This condition can be due to the high weight of the head in the elephant. To maintain this weight, it is necessary to reduce the length of the neck and confer less mobility.

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Deformations of the Cervical and Cranial Thoracic Vertebrae in a Bedridden Asian Elephant

Cited by 2 publications

References 8 publications

Truly dorsostable runners: Vertebral mobility in rhinoceroses, tapirs, and horses

Truly dorsostable runners: Vertebral mobility in rhinoceroses, tapirs, and horses

CT anatomy of cervical vertebrae of Asian elephant (Elephas maximus)

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