+ Cats

  • Cardiac neoplasia is uncommon in cats and dogs
  • Incidence of cardiac neoplasia in cats is 0.03%
  • LSA is the most common feline cardiac tumor (31%)
  • Other cardiac tumors include metastatic carcinomas (19%), HSA (8.6%), chemodectoma (3.4%), and FSA (3.4%)

+ Dogs

  • Incidence of cardiac neoplasia in dogs is 0.19%
  • Spayed female dogs have a 338% increased risk of developing a cardiac tumor than intact female dogs
  • Castrated male dogs have a 63% increased risk of developing a cardiac tumor than intact male dogs
  • Breeds with an increased risk of cardiac tumors include Saluki, French Bulldog, Irish Water Spaniel, Flat-Coated Retriever, Golden Retriever, Boxer, Afghan Hound, English Setter, Scottish Terrier, Boston Terrier, Bulldog, and German Shepherd Dog
  • Right atrial HSA and aortic body chemodectomas are the most commonly reported cardiac tumors
  • Other reported cardiac tumors include non-atrial HSA, LSA (2.5%-3.9%), ectopic thyroid carcinoma (0.9%-2.9%), FSA, CSA, rhabdomyosarcoma, pericardial mesothelioma, fibroma, and myxoma
  • Primary cardiac LSA tends to occur in younger dogs
  • Surgical resection of intramural or intracavitary cardiac tumors is rarely attempted in cats or dogs
  • Intracardiac ectopic thyroid tumor resection via right ventriculotomy under hypothermia and total venous inflow occlusion has been reported
  • Surgical resection under total venous inflow occlusion or cardiopulmonary bypass should be considered for well-defined primary cardiac tumors
  • However, majority of cardiac tumors in small animals are malignant and are not good surgical candidates
  • Primary cardiac tumors are more common than metastatic tumors (in contrast to humans where metastatic tumors are 20-40 times more common than primary cardiac tumors)
  • Primary tumors metastasizing to the heart include non-cardiac HSA (34%), ADC (21%), OSA (6%), MCT (< 5%), and various other sarcomas (< 5%)