Congenital Cardiac Abnormalities in Elephants and Lagomorphs

Summary Information
Diseases / List of Miscellaneous / Metabolic / Multifactorial Diseases / Disease summary
Alternative Names
  • Tetralogy of Fallot
  • Patent ductus arteriosus
  • Ventricular septal defect
  • Pulmonary valve stenosis
  • Vestigial/absent ascending aorta
Disease Agents
  • In Elephants: Unknown.
  • In Lagomorphs: Can be hereditary. In one population of IIIVO/J rabbits, defects were seen in rabbits homozygous for both of two autosomal recessive factors. (J346.66.w1)
Infectious Agent(s) --
Non-infectious Agent(s) --
Physical Agent(s) --
General Description
In Elephants
Clinical signs
  • In a male, full term Elephas maximus - Asian Elephant calf with tetralogy of Fallot. (P67.2000.w1)
    • Weakness, inability to stand. (P67.2000.w1)
    • Inability to nurse. (P67.2000.w1)
    • Reduced temperature of the ears and extremities. (P67.2000.w1)
    • No abnormal heart sounds on auscultation. (P67.2000.w1)
    • Death nine hours after birth (from hypoxia). (P67.2000.w1)
  • In a male, full term Elephas maximus - Asian Elephant calf with tetralogy of Fallot. (P67.2000.w1)
    • Cardiac abnormalities only were found:
      • In the interventricular septum, a sub-aortic ventricular septal defect, 4.0 by 5.0 cm. (P67.2000.w1)
      • Overriding aorta, allowing emptying of both ventricles into the aorta. (P67.2000.w1)
      • Aortic valve circumference was 23.0 cm, pulmonary valve circumference was 13.5 cm. (P67.2000.w1)
      • There were no histopathological lesions. (P67.2000.w1)
  • In two neonates, patent ductus arteriosus. (B450.14.w14)
In Lagomorphs
Clinical signs
  • Dyspnoea was the presenting sign in a rabbit with a ventricular septal defect (J29.10.w1) while respiratory distress together with severe diffuse cyanosis developed in a young (less than one year old) rabbit with Eisenmenger's syndrome. (J495.45.w1)
  • Reported defects [not including those associated with experimentally treated rabbits] include:
    • Ventricular septal defects.
      • Ventricular septal defects were noted in 0.078% of Himalayan rabbits in one study (6/7707 fetuses). (J83.37.w1)
      • Venticular septal defect was diagnosed with echocardiography in a rabbit with chronic dyspnoea. (J29.10.w1)
      • Ventrticular septal defect with Eisenmenger's syndrome ("pulmonary hypertension due to high resistance of the pulmonary vasculature bed with reversed or bidirectional shunts at he ventricular, atrial, and/or aorticopulmonary levels" in a nine-month old laboratory (New Zealand white) rabbit. (J495.45.w1)
    • Absent or vestigial pulmonary arterial trunk.
    • Stenosis of the pulmonary valve.
    • Absent or vestigial ascending aorta, sometimes with bulbous pulmonary trunk.
    • Ectopia cordis
    • Cor biloculare
    • Dextrocardia
    • Stenosis of vessels.
    • Ductus arteriosus closure.
    • Dilated ventricle; this was noted in 12/7707 fetuses of Himalayan rabbits in one study. (J83.37.w1)
    • Persistent truncus arteriosus and persistent foramen interventriculare (1/7707 fetuses, 0.013%). (J83.37.w1)
    • Cortriloculare and persistent truncus arteriosus (united with the carotids and subclavian artery). (J83.37.w1)
    • Persistent truncus arteriosus (3/7707 fetuses, 0.039%). (J83.37.w1)
    • Cortriloculare and persistent truncus arteriosus (1/7707 fetuses, 0.013%). (J83.37.w1)
    • Atria of heart dilated (1/7707 fetuses, 0.013%). (J83.37.w1)
    • Hypoplasia of heart (2/7707 fetuses, 0.026%). (J83.37.w1)
    • Heart constricted (1/7707 fetuses, 0.013%). (J83.37.w1)
    • Apex of heart directed to the right side (3/7707 fetuses, 0.039%). (J83.37.w1)

    (B601.10.w10, B611.5.w5, J83.37.w1, J346.66.w1, J495.45.w1)

Further Information
In Elephants
  • Tetralogy of Fallot was found in a male, full term Elephas maximus - Asian Elephant calf of 131.5 kg, delivered to a primiparous 39-year-old cow following a difficult labour. (P67.2000.w1)


  • In two neonates, patent ductus arteriosus was detected at necropsy. (B450.14.w14)
  • In a male, full term Elephas maximus - Asian Elephant calf with tetralogy of Fallot. (P67.2000.w1)
    • The lesions found were compatible with the tetralogy of Fallot, which includes a sub-aortic defect of the ventricular septum, overriding aorta, pulmonic stenosis and secondary right venticular hypertrophy. (P67.2000.w1)
      • Since the right ventricle is normally hypertrophied in the fetus, it was not possible to determine whether this point of the tetralogy was present. (P67.2000.w1)
    • Pulse oximetry using a rectal probe, if attempted, might have been useful to detect reduced circulation. (P67.2000.w1)
    • Cardiac ultrasonography could have assisted diagnosis (but would not have affected the outcome). (P67.2000.w1)
In Lagomorphs
  • Congenital cardiac defects are rare except in experimentally treated rabbits. (B601.10.w10, B602.21.w21, B611.5.w5, J83.37.w1)
  • Depending on the severity of the abnormality, it may be immediately lethal to the newborn, or the affected individual may live for a short time. (J346.66.w1) There are occasional reports of cardiac abnormalities detected in older rabbits:
    • A ventricular septal defect was detected by echocardiography in a rabbit presenting with chronic dyspnoea. (J29.10.w1)
    • A laboratory rabbit with a ventricular septal defect was clinically normal to eight months of age when it developed respiratory distress and severe cyanosis. (J495.45.w1)
Associated Techniques
Host taxa groups /species
Disease Author Debra Bourne MA VetMB PhD MRCVS (V.w5)
Referees Brigitte Reusch BVet Med (Hons) CertZooMed MRCVS (V.w127)

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