Auscultatory, echocardiographic, biochemical, nutritional, and environmental characteristics of mitral valve disease in Norfolk terriers

• Published in: Journal of veterinary cardiology 2012-03, Vol.14 (1), p.261-267
• Main Authors: Trafny, Dennis J., Freeman, Lisa M., Bulmer, Barret J., MacGregor, John M., Rush, John E., Meurs, Kathryn M., Oyama, Mark A.
• Format: Article
• Language: English
• Subjects: Animals; Biomarkers; Dog Diseases - pathology; Dogs; Echocardiography - veterinary; Female; Heart murmur; Male; Mitral Valve - diagnostic imaging; Mitral Valve Insufficiency - veterinary; NT-proBNP; Nutrition; Risk Factors; Serotonin
• ISSN: 1760-2734; 1875-0834
• DOI: 10.1016/j.jvc.2011.10.002

In order to more fully understand degenerative mitral valve disease (DMVD) in the Norfolk terrier, we sought to characterize findings from the physical and echocardiographic examination; biochemical, biomarker, and nutritional profiles; and select environmental variables from a cohort of apparently healthy Norfolk terriers. Overtly healthy Norfolk terriers ≥6 yrs old were recruited by 3 different veterinary hospitals and underwent historical, physical, electrocardiographic (ECG), and 2D/color-flow Doppler echocardiographic examinations. Anterior mitral valve leaflet length, maximal thickness, area, and degree of prolapse were measured or calculated from two-dimensional images. Blood samples were obtained for serum biochemistry, serum serotonin, plasma NT-proBNP, amino acid profile, C-reactive protein, and cardiac troponin I. Of the 48 dogs entered into the study, 23 (48%) had murmurs, 2 (4%) had mid-systolic clicks, 11 (23%) had ECG P pulmonale, and 41 (85%) were deemed to have echocardiographic evidence of DMVD, including 18 Norfolk terriers without a murmur. Seven (15%), 28 (58%), and 13 (27%) dogs were classified as normal (stage 0), International Small Animal Cardiac Health Council (ISACHC) stage 1a, and 1b, respectively. Mean indexed echocardiographic mitral leaflet thickness (P = 0.017), area (P = 0.0002), prolapse (P = 0.0004), and left atrial to aortic diameter (P = 0.01) were significantly different between ISACHC 0, 1a, and 1b. DMVD is relatively common in Norfolk terriers and echocardiographic changes consistent with mild DMVD can be seen in dogs without a heart murmur.