Lesson 8 of 9
In Progress

How Congenital Heart Failure Differs in Cats and Dogs

  1. Incidence:
    • Less common in cats than dogs
  2. Breed, Sex:
    • No overall breed or sex predilection in cats
  3. Frequency of congenital disorders:
    1. A-V valve insufficiency – (17%)
    2. Ventricular septal defect – (15%)
    3. Endocardial fibroelastosis – (11%)
    4. Patent ductus arteriosus – (11%)
    5. Aortic stenosis – (6%)
    6. Tetralogy of Fallot – (6%)
  4. General Comments:
    • A-V valve insufficiency:
      • if severe – heart failure and death likely occur in the first few weeks of life
      • most cases are likely mild with no symptoms but do have a heart murmur of mitral or tricuspid regurgitation
      • a great deal of data is lacking with respect to the significance of this disorder
    • Ventricular septal defect:
      • the prognosis of this disorder depends on the size of the defect
      • it is well known that many cats can have small defects and live long normal lives
      • the clinical picture is identical to that of the dog
      • in that spontaneous closure of VSD is common in man, it may also occur in cats
      • in that VSD forms a part of a number of other complex anomalies, the VSD disorder is considered by many to be the most common defect in the cat
    • Endocardial fibroelastosis (EFE):
      • primarily seen in Burmese and Siamese cats
      • a fatal short coursed disorder in young cats (3 wk to 4 months) characterized by fibrosis of the ventricular endocardium causing a marked loss in distensibility
      • LV and left atrial dilation occur with fulminant heart failure
      • no treatment is effective
    • Patent ductus arteriosus:
      • some cats may die with this disorder soon after birth
      • it is reported that if they survive the immediate neonatal period, most will develop signs of CHF and die by one year of age
      • the incidence of reverse PDA in cats is said to be 15-20% of cases of PDA
      • the clinical picture is as for dogs with PDA
      • surgical correction is the only definitive cure
    • Aortic stenosis:
      • A.S. is usually supravalvular in the cat
      • the clinical picture is as for dogs
    • Tetralogy of Fallot:
      • similar to the dog in presentation and clinical course