GENERAL CONSIDERATIONS

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%)