Vertebral scale system to measure heart size in thoracic radiographs of Indian Spitz, Labrador retriever and Mongrel dogs

Aim: To establish reference values of vertebral heart score (VHS) in Indian Spitz, Labrador retriever, and Mongrel dogs; to assess applicability of VHS in these three dog breeds; to determine if breed, recumbency side, gender, body weight, and thoracic depth (TD) to thoracic width (TW) ratio has an influence on the VHS measurement in these dog breeds. Materials and Methods: A total of 60, client owned, clinically healthy Indian Spitz (n=20, mean age = 4.25±2.15 years, body weight = 11.87±2.7 kg), Labrador retriever (n=20, mean age = 4.75±1.91 years, body weight = 27.31±5.43 kg), and Mongrel dogs (n=20, mean age = 4.25±1.52 years, body weight = 16.25±3.99 kg), having no radiological and clinical signs of cardiovascular or pulmonary disease were included in the study. All dogs were restrained manually and left lateral (LL) and right lateral (RL) radiographic views were obtained. The size of heart in lateral radiographs was calculated using VHS method. Besides, the TD, TW and TD: TW were calculated to determine the type of thoracic conformation in the dog breeds. In addition to this, the effect of breed, side of recumbency, gender, body weight, and TD to TW ratio on the calculation of VHS was determined. Results: VHS was calculated in all the animals of the breeds. VHS in Spitz and Labrador retriever was significantly (p9.7±0.5 v. RL and LL VHS in Mongrel dog was significantly (p9.7±0.5 v. Significant (p