Severity and prognosis of cardiac disease is frequently difficult to assess. Several studies investigated laboratory parameters, cardiac biomarkers and echocardiographic parameters for their potential to detect congestive heart failure (CHF) and their prognostic reliability. The relevance of cardiorenal syndrome in progression of cardiac disease is of increasing interest in human medicine, but its importance in veterinary medicine is not known.

Case records were reviewed retrospectively from dogs with naturally occurring or suspected cardiac disease presented to the cardiology service of the University of Liverpool between December 2008 and February 2011. Patients were categorized according to their heart failure class. Signalment, physical examination, blood pressure, laboratory parameters, cardiac troponin I (cTnI) and echocardiographic investigations obtained at the first visit, survival and survival times were analysed.

168 client owned dogs were included in the study. 43 dogs had no cardiac disease, 91 were in heart failure class B, 27 in class C, 7 in class D. Most frequent cardiac diseases were degenerative valvular disease (n = 34), patent ductus arteriosus (n = 17) and dilated cardiomyopathy (n = 16). Higher heart rate, increased renal parameters, cTnI, left atrium to aortic ratio and E wave to isovolumetric relaxation time were associated with CHF and reduced survival times.

These results show the importance of heart rate control in cardiac patients, as reported in human medicine. Several parameters for CHF and survival were detected, similar to previous reports. Renal parameters were associated with CHF and survival, which suggests that cardiorenal syndrome might play a role in progression of canine cardiac diseases.