Methods– Single center prospective cohort study. Auscultation and standard echocardiograms were performed by board-certified cardiologists. Longitudinal echocardiograms were performed in a subset.
Results– The population consisted of 86 females (58.9%) and 60 males (41.1%). Median age was 4 years (range 1.1-12.0). Heart murmurs were identified in 86/146 dogs (58.9%). Most Borzoi were structurally normal (119/146, 81.5%), with 64 normal dogs (43.8% of the total population) having an innocent heart murmur. Thirty-six structurally normal dogs had trace or mild mitral regurgitation (30.2% of normal dogs) and 43 had trace or mild tricuspid regurgitation (36.1% of normal dogs). Structural cardiac disease was identified in 21 dogs (14.4%), with another six dogs having equivocal diagnoses (4.1%). Dilated cardiomyopathy (DCM) was diagnosed in nine dogs (6.2%) and stage B1 myxomatous mitral valve disease (MMVD) was diagnosed in nine dogs (6.2%). Twenty-five dogs had longitudinal examinations. Two dogs developed occult DCM, two transitioned to an equivocal DCM diagnosis, and two developed stage B1 MMVD within two years. Two dogs with DCM (one occult, one equivocal) improved with diet change.
Conclusions and clinical importance– Structurally normal Borzoi commonly have trace or mild atrioventricular valve insufficiencies and innocent heart murmurs. All Borzoi with MMVD had normal heart size. Screening for DCM may be considered in the breed.
