Norwich terriers possess a greater vertebral heart scale than the canine reference value

Abstract

Previous studies have demonstrated evidence that normal reference ranges for radiographic vertebral heart scale values can vary among dog breeds. The purpose of this retrospective, observational study was to determine whether the normal vertebral heart scale values published by Buchanan and Bücheler for lateral radiographs are applicable to the Norwich terrier. Secondary objectives were to determine if clinical signs of respiratory disease, age, sex, weight, body condition score, recumbency, or thoracic depth‐to‐width ratio had any influence on vertebral heart scale measurements in this breed. The electronic medical record systems of two universities were reviewed and Norwich terriers were included in the study if they had orthogonal thoracic radiographs performed and no historical or radiographic evidence of cardiopulmonary disease. A vertebral heart scale was calculated for each patient. Sixty‐one client‐owned, Norwich terrier dogs with no clinical signs of cardiovascular disease were evaluated. The vertebral heart scale for Norwich terriers without evidence of cardiac disease (10.6 ± 0.6) was found to be significantly greater than the canine reference value of 9.7 ± 0.5 initially established by Buchanan and Bücheler. No significant correlation was found between clinical signs of respiratory disease, sex, age, thoracic depth‐to‐width ratio or lateral recumbency, and vertebral heart scale. Norwich terriers with a body condition score ≥6 had a significantly higher vertebral heart scale than those with a body condition score ≤5. Breed‐specific ranges and body condition scores need to be considered when interpreting vertebral heart scale values for Norwich terriers.

Radiographic vertebral left atrial size: A reference interval study in healthy adult dogs

“…For intraobserver and interobserver measurement agreement, VLAS and VHS showed an almost perfect agreement. This finding provides evidence that VLAS and VHS are repeatable methods for measuring cardiac chamber size, as confirmed by previous studies 10,11,13 . Further studied are needed to verify if veterinarians with different clinical experience and specialization (eg, general practitioners, cardiologists, intensive care clinicians) have the same measurement variability.…”

“…First, the possible influence of the body condition score on VLAS was not evaluated. Previous studies have reported the possible influence of body condition score on VHS 7,9,11 . However, all dogs included in the study were healthy, and no obese or cachectic dogs were present in the study population.…”

“…The vertebral heart score (VHS) is the most commonly used method for the objective evaluation of cardiac size in thoracic radiographs in dogs 3 . Differences in VHS according to the canine breed have also been described 4‐11 . However, there are few studies in veterinary medicine aimed at standardizing the radiographic left atrial (LA) size 12‐15 …”

A radiographic study of breed‐specific vertebral heart score and vertebral left atrial size in Chihuahuas

“…4 Previous studies have highlighted interbreed VHS differences, establishing that the VHS reference ranges of some breeds significantly differ to those proposed by Buchanan and Bucheler. [5][6][7][9][10][11][12][13][14][15] Consequently, the previously established mean normal value of 9.7 ± 0.5 vertebrae cannot be applied to all canine breeds.…”

“…4 The VHS is influenced by different breed-specific morphotypes, and several studies have described a breed-specific reference range for the VHS. [5][6][7][8][9][10][11][12][13][14][15] The vertebral left atrial size (VLAS) has recently been proposed as a new radiographic method for the evaluation of left atrial size in dogs 16 ; however, no studies have evaluated VLAS variations in relation to different breeds. The Chihuahua is predisposed to the development of both congenital and acquired cardiac disease.…”