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Tetralogy of Fallot

Overview, Diagnosis, and Prognosis

Tetralogy of Fallot is a congenital heart defect consisting of four abnormalities that affect the heart’s ability to pump enough oxygenated blood to the body (Eldredge, et. al., 2007). Statistics on prevalence of tetralogy of fallot in dogs and cats were not found in the literature. The four abnormalities that make up Tetralogy of Fallot are as follows:

  1. Pulmonary stenosis – a narrowing of the right ventricular outflow tract
  2. Overriding aorta – an aortic valve is situated above the septal defect and connected to both the right and left ventricle
  3. Ventricular Septal Defect – a hole between the two bottom chambers (ventricles) of the heart
  4. Right Ventricular Hypertrophy – the right ventricle is more muscular than normal, which causes a boot-shaped appearance as seen by x-ray (, visited on 10/20/2010).

Symptoms and Treatment

Symptoms and treatment for Tetralogy of Fallot are similar to those of other congenital heart diseases (see Valvular Dysfunction and Cardiomyopathy). The literature does not suggest that surgery is readily available for dogs or cats born with this disease.