Breed-specific vertebral heart score, vertebral left atrial size, and radiographic left atrial dimension in Cavalier King Charles Spaniels: Reference interval study.

Mara Bagardi,Sara Ghilardi,Paola G. Brambilla,Martina Manfredi,Davide D. Zani,Carlotta Spediacci,Jessica Bassi,Chiara Locatelli

doi:10.1111/vru.13036

Abstract

Cavalier King Charles Spaniels (CKCS) are predisposed to developing myxomatous mitral valve disease (MMVD), with radiographs frequently used to screen for evidence of left‐sided cardiomegaly secondary to MMVD. Vertebral heart size (VHS), vertebral left atrial size (VLAS), modified VLAS (M‐VLAS), and radiographic left atrial dimension (RLAD) are reported as objective measurements of global heart size and left atrial size. Normal VHS in CKCS (10.6 ± 0.5) is reportedly higher than the non‐breed‐specific value (9.7±0.5). Breed‐specific VLAS, M‐VLAS, and RLAD cut‐offs have not been reported in CKCS. The aim of this prospective reference interval study was to describe the VHS, VLAS, M‐VLAS, and RLAD values for 30 clinically healthy adult CKCS. Inclusion criteria were unremarkable physical examination, normal echocardiography, and thoracic radiographs without malposition/abnormalities. There were 22 female and eight male dogs. Ages ranged from 1 to 6 years. The VHS mean value in our sample was 10.08 ± 0.56 (95% range, 9.87‐10.29). This was significantly greater than a previously published general canine reference value of 9.7 ± 0.5 and significantly less than a previously published CKCS breed‐specific value of 10.6 ± 0.5 (P < 0.01). Mean VLAS, M‐VLAS, and the RLAD values in our study were 1.79 ± 0.3 (95% range, 1.68‐1.9), 2.23 ± 0.44 (95% range, 2.06‐2.39), and 1.2 ± 0.34 (95% range, 1.07‐1.33), respectively. These were significantly less than previously published reference interval values (P < 0.001). The VHS, M‐VLAS, and the RLAD were not affected by sex, body weight, or BCS; whereas the VLAS was moderately affected by body weight. Findings from this study can be used as background for future thoracic radiographic assessments in CKCS.

Highlights

2.1 Ethical approvalMyxomatous mitral valve disease (MMVD) is a common cardiovascular disease affecting dogs, progressing to mitral regurgitation, and eventually heart failure.[1]
Fifty percent of Cavalier King Charles Spaniels (CKCS) are affected by the age of 6-7 years, and almost 100% are affected by the age of 11.1,2 In this breed, thoracic radiographs are frequently used to screen for evidence of left-sided cardiomegaly secondary to myxomatous mitral valve disease (MMVD).[3,4]
Healthy CKCS referred for preoperative evaluation or cardiologic screening were recruited from June 2019 to March 2021 at the Veterinary Medicine Department of the University of Milan

Summary

Introduction

Myxomatous mitral valve disease (MMVD) is a common cardiovascular disease affecting dogs, progressing to mitral regurgitation, and eventually heart failure.[1] The incidence is age-related and is high in breeds such as the Cavalier King Charles Spaniels (CKCS).[1,2] Fifty percent of CKCS are affected by the age of 6-7 years, and almost 100% are affected by the age of 11.1,2 In this breed, thoracic radiographs are frequently used to screen for evidence of left-sided cardiomegaly secondary to MMVD.[3,4] Published radiographic measures of heart size include vertebral heart size (VHS), vertebral left atrial size (VLAS), its modified version (M-VLAS), and radiographic left atrial dimension (RLAD).[3,5,6,7,8,9] The VHS is influenced by different morphotypes and several studies have described breed-specific reference range.[10,11,12,13,14,15,16,17,18,19,20] Only normal values of VHS in CKCS have been investigated and are reported to be higher than not-breed-specific reference ranges (respectively 10.6 ± 0.5 vs 9.7 ± 0.5).[3,10]

Objectives

Methods

Results

Conclusion