Download congenital defects: tetralogy of fallot

CONGENITAL DEFECTS: TETRALOGY OF
FALLOT
Keeshonds are the most commonly affected breed,
but bulldogs and cats have increased incidence as well.
Cause: polygenic inheritance
CONGENITAL DEFECTS: TETRALOGY OF
FALLOT
• THERE ARE 4 MAIN ANATOMICAL
ABNORMALITIES IN THIS DISEASE!
– Pulmonic stenosis
– Right ventricular hypertrophy
– Ventricular septal defect
– Overriding aorta
CONGENITAL DEFECTS: TETRALOGY OF
FALLOT
• CLINICAL SIGNS and DIAGNOSIS:
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Affected puppies are smaller than littermates
Exercise intolerance
Dyspnea, tachypnea
Syncope
Cyanosis
Polycythemia: occurs as a response to the large amount
of deoxygenated blood going to the systemic circulation
– Systolic murmur over the pulmonic area
– ECHO: right ventricular hypertrophy, subaortic
ventricular septal defect, right outflow tract obstruction
CONGENITAL DEFECTS: TETRALOGY OF
FALLOT
• TREATMENT:
– Phlebotomy: to keep PCV below 65%
– Surgery:
• Create a left–to–right shunt by doing systemic artery to
pulmonary artery anastamosis
• Complete correction requires cardiopulmonary bypass
which is uncommon in animals
CONGENITAL DEFECTS: TETRALOGY OF
FALLOT
• CLIENT INFO:
– These dogs should not be bred
– Congestive heart failure rarely develops
– Affected animals need regular phlebotomy
– Limit stress and exercise
CONGENITAL DEFECTS: PERSISTENT RIGHT 4TH
AORTIC ARCH
Great Danes, German Shepherds, Irish Setters
are most commonly affected
CONGENITAL DEFECTS: PERSISTENT RIGHT 4TH
AORTIC ARCH
CONGENITAL DEFECTS: PERSISTENT RIGHT 4TH
AORTIC ARCH
Clinical signs include regurgitation due to megaesophagus,
aspiration pneumonia, dyspnea, weight loss
CONGENITAL DEFECTS: PERSISTENT RIGHT 4TH
AORTIC ARCH
• TREATMENT: Early surgical correction
– Prognosis is poor without surgery
– Even with surgery, some esophageal dilation may
persist
• CLIENT INFO:
– These dogs should not be used for breeding