Radiographic evaluation of congenital vertebral anomalies in Korean raccoon dogs (Nyctereutes procyonoides koreensis)

Abstract

Background The normal vertebral anatomy of Korean raccoon dogs and their variants require research attention as a prerequisite for identifying pathologies and anomalies. Objectives This retrospective study aimed at describing the vertebral formula and congenital vertebral anomalies in Korean raccoon dogs ( Nyctereutes procyonoides koreensis ). Methods Radiographs of 82 raccoon dogs (42 males, 40 females) acquired from May 2013 to June 2020 in the Gangwon Wildlife Medical Rescue Center were reviewed to evaluate the cervical, thoracic, and lumbar vertebrae of the spine. Results Normal morphology of all vertebrae was observed in 50 of the 82 raccoon dogs, and the vertebral formula was cervical 7, thoracic 13, and lumbar 7. Congenital vertebral anomalies were found in 32 raccoon dogs: transitional vertebrae (TV) in 31 and block vertebrae in 2. Two raccoon dogs had 2 types of vertebral anomalies: one had TV and block vertebra, and the other had 2 types of TV. Twenty-nine raccoon dogs had thoracolumbar TV (TTV) and 3 had lumbosacral TV. TTV was morphologically classified into 4 different types: unilateral extra-rib in 5 raccoon dogs, bilateral extra-ribs in 14, bilateral elongated transverse processes in 4, and an asymmetric mixed formation of extra-rib with elongated transverse process in 6. Conclusions This study showed that TTV is common in Korean raccoon dogs, and that the vertebral formula is relatively diverse. The bilateral extra-ribs type TTV is the most common variant, which is almost similar to normal rib to be confused the radiographic evaluation.

Transitional and/or Supernumerary Vertebra in Lumbosacrocaudal Region of the Spine – a Reality in All Domestic Mammals

“…The largest description of transitional vertebrae regarding the localization, the morphology, clinical significance and prevalence exist in dogs [8,18,19]. Such anomalies, as well as others (hemivertebrae, wedge vertebrae, block vertebrae, atlantoaxial malformations and spina bifida) and their prevalence have been described also in cats, ferrets [20][21][22][23]. In other domestic mammals the reports regarding the presence and type of transitional vertebrae are even less, for that we proposed to investigate the lumbosacrocaudal spine in as many species as possible, to have a comparative view, not only radiologically, but especially anatomical analysis.…”