Skip to main content
Research article - Peer-reviewed, 2021

The Longitudinal Outcome Of Canine (K9) myxomatous mitral valve disease (LOOK- Mitral registry): Baseline characteristics

Franchini, A.; Borgarelli, M.; Abbott, J. A.; Menciotti, G.; Crosara, S.; Haggstrom, J.; Lahmers, S.; Rosenthal, S.; Tyrrell, W.


Introduction: The Longitudinal Outcome Of Canine (K9) myxomatous mitral valve disease (MMVD) registry (LOOK-Mitral registry) was established to de-scribe the natural history and predictors of outcome in dogs affected by MMVD. This study was intended to describe the baseline characteristics of dogs in the LOOK-mitral registry. Animals: Dogs with echocardiographic evidence of MMVD were prospectively enrolled by thirteen referral centers. Results: A total of 6102 dogs with MMVD were included. The median age was 10 years (1e19 years), and mixed breed was the most common breed (n 1/4 1,360, 22%). Concomitant diseases were reported in 2459 dogs with chronic respiratory diseases occurring most frequently (14%), followed by the presence of azotemia (6%) and orthopedic diseases (5%). Regarding disease severity, 65% of dogs were in ACVIM Stage-B1, 15% in Stage-B2, and 20% in Stage-C. Dogs in Stage-B1 were younger (p<0.001) than dogs in other stages. Murmur intensity, heart rate during physical examination, and radiographic vertebral heart score were positively associated with the stage. Dogs in Stage-C were more likely to have tachypnea (p<0.001), dyspnea (p<0.001), cough (p<0.001), syncopal episodes (p<0.001), and tachyarrhythmias (p<0.001) compared to dogs in Stage-B1 and B2. Echocardiographic indices of left atrial and ventricular size were positively correlated with the ACVIM stage. Interestingly, 4% of dogs that weighed <20 kg had an increased normalized end systolic left ventricle internal diameter (>1.26). Conclusions: This study contributes to a better understanding of the clinical characteristics of dogs affected by MMVD and provides new findings that may be of clinical relevance. 2021 Elsevier B.V. All rights reserved.


Dogs; Degenerative valvular disease; Echocardiography

Published in

Journal of Veterinary Cardiology
2021, volume: 36, pages: 32-47
Publisher: ELSEVIER

Authors' information

Franchini, A.
Virginia Polytechnic Institute and State University
Borgarelli, M.
Virginia Polytechnic Institute and State University
Abbott, J. A.
UT Institute of Agriculture
Menciotti, G.
Virginia Polytechnic Institute and State University
Crosara, S.
University of Parma
Swedish University of Agricultural Sciences, Department of Clinical Sciences
Lahmers, S.
Virginia Polytechnic Institute and State University
Rosenthal, S.
CVCA Cardiac Care Pets
Tyrrell, W.
CVCA Cardiac Care Pets

UKÄ Subject classification

Clinical Science

Publication Identifiers


URI (permanent link to this page)