Congenital heart defects in dogs range from mild to life-threatening, with welfare outcomes depending on defect type, severity, and access to appropriate management.
Congenital heart defects create welfare challenges that begin at birth and may limit the dog's entire lifetime. PDA, while correctable if caught early, causes progressive cardiac overload that can cause heart failure if uncorrected. The welfare benefit of PDA correction is substantial - a potentially fatal condition converted to one with normal life expectancy. Pulmonic stenosis causes right heart strain that limits exercise tolerance, with welfare improvement after balloon valvuloplasty allowing more normal activity. Subaortic stenosis creates chronic welfare compromise through exercise limitation, syncope risk, and the anxiety of managing a condition that may cause sudden death. Heritable congenital defects require breeding exclusion of affected animals to reduce their frequency in subsequent generations.