Research Communications of the 24th ECVIM-CA Congress

No conflicts of interest reported. Ventricular septal defect (VSD) is the fourth most common congenital cardiac defect in dogs and the most common in cats. The aim of this study was to evaluate the long-term outcome in VSD patients. Case records of 95 animals were reviewed, 46 of these re-evaluated echocardiographically and 49 followed up by phone interview only. Out of 53 dogs Pug was the most common breed (11%) followed by Border Terrier (8%). Out of 42 cats Domestic Short Hair was most common (55%) followed by Main Coon (19%). Isolated VSDs were present in 29 dogs and 26 cats. Complex defects (CDs) were present in 40 cases, most frequent anomalies being sub-aortic stenosis (9 dogs, 1 cat), pulmonic stenosis (5 dogs, 3 cats), Tetralogy of Fallot (3 dogs, 2 cats), cushion defects (5 cats) and double-chambered right ventricle (DCRV) (5 dogs, 4 cats; in 2/5 dogs not present initially supporting the cause-and-effect theory). Eisenmenger was observed in 1 dog and 2 cats. Aortic insufficiency, not considered a CD, was noted in 10 dogs. In 3 dogs and 6 cats (15% of isolated VSDs and 1 cat with a DCRV) the defect closed spontaneously. Nine dogs and 9 cats (22%) died of non-cardiac causes with an age at death of 5 to 204 (mean 63.8) months; 7 dogs and 8 cats died due to cardiac causes with an age at death of 0.25 to 204 (mean 37.5) months. Cardiac deaths were sudden (2 dogs with CDs) or euthanasia for left sided congestive heart (CHF) failure associated with CDs (3 dogs, 1 cat); right sided CHF associated with CDs (2 cats); biventricular failure (1 cat with CD); weakness (Eisenmenger, 1 dog and 1 cat; Fallot 1 dog; CD 1 cat). Two cats developed CHF due to unrelated HCM. Only one dog with an isolated VSD was euthanized for CHF.