Because data obtained in human trials show that early intervention with an ACE inhibitor may delay the development of congestive heart failure, several veterinarians have increased their interest in using ACE inhibitors as cardio protective therapy to postpone or prevent congestive heart failure in dogs affected by early mitral valve disease. However, a previous Scandinavian study of 229 asymptomatic Cavalier King Charles spaniels (CKCS) with mild mitral valve regurgitation has shown that long term ACE inhibitor application did not delay the onset of congestive heart failure in asymptomatic CKCS with mild mitral valve regurgitation.