2017 ACVIM Forum Research Abstract Program

CT-BASED ANATOMICAL FEATURES OF LARGE AIRWAY AND HEART VOLUME IN DOGS WITH DIFFERENT BODY SIZE. T. Uehara, Y. Fujii, K. Sugimoto, H. Sunahara, T. Aoki. Azabu University, Sagamihara, Kanagawa, Japan Chronic valvular heart disease is commonly seen in small-breed dogs and a cough is a common clinical sign. We hypothesized that anatomical features of the heart and large airway were different, influenced by body size, and would relate to coughing when the heart enlarged. The purpose of this study was to compare relative heart volume and anatomical features of large airway in different body sizes using CT scan. Retrospective analyses performed on medical records of dogs without heart and lung disease that underwent CT scanning. Dogs (n = 209) were divided into 3 groups on the basis of body weight; small (<7 kg), medium (7 kg-20 kg), and large (≥20 kg). The following parameters were calculated using OsiriX: thoracic volume, heart volume, relative heart volume to thoracic volume, heart length, distance from main stem bronchi to vertebra, tracheal diameter, and angle of bronchus. Relative heart volume was significantly large in small dogs (0.29 AE 0.070) and medium dogs (0.28 AE 0.061), compared with large dogs (0.23 AE 0.075). The relative distance from main stem bronchi to vertebra was significantly short in small dogs (0.10 AE 0.037), compared with medium (0.15 AE 0.043) and large dogs (0.19 AE 0.050). There was no significant difference in the angle of bronchus among the groups. Findings revealed that small dogs had a large heart relative to the thorax, and the distance from the heart to vertebra was relatively short, compared with larger dogs. This anatomical feature may be potentially predisposed to occurrence of cough.