Radiographic Evaluation of Vertebral Heart Scale and Caudal Vena Cava Size Useful for Diagnosing Cardiac Diseases in Endangered Long-Tailed Goral (Naemorhedus caudatus)

Abstract

Although various imaging evaluation methods have been developed and utilized, thoracic radiography remains essential and is the top priority for diagnosing and managing cardiac diseases. Thoracic radiographic measurements associated with the vertebral heart scale (VHS) and caudal vena cava (CVC) can objectively diagnose cardiac disease in many animals. In particular, VHS measurement is primarily used to evaluate the dimensions of the heart size on thoracic radiographs and can measure cardiomegaly more objectively. Additionally, the value of the CVC compared with the aorta (Ao) and the length of vertebrae (VL) can be used as valuable parameters in right congestive heart failure. To describe the CVC/Ao and CVC/VL ratios in 10 long-tailed gorals (Naemorhedus caudatus) without subjective radiographic evidence of cardiac diseases. The VHS, CVC, Ao, and VL of gorals were measured in the right lateral (RL) view of the thoracic radiographs. In the RL view of 10 gorals, the VHS was 9.31 ± 0.55 vertebrae (v), the CVC/Ao ratio was 0.84 ± 0.13, and the CVC/VL ratio was 0.67 ± 0.09. Additionally, the thoracic morphology of gorals was determined to be intermediate (thoracic depth-to-width ratio, 1.04 ± 0.09, 0.75-1.25). This study confirmed that VHS was significantly correlated with CVC and Ao, and measuring and comparing each value would help diagnose cardiac diseases in gorals. The radiographic measurements in this study will allow veterinarians to diagnose several cardiac diseases in gorals.