CHEMODECTOMA IN DOGS

Tumors of the chemoreceptor organs are referred to as chemodectomas. S uch tumors develop principally in the aortic and carotid bodies of ani mals. Aortic body tumors occur four times more frequently than do caro tid body tumors. Brachycephalic breeds (e.g., boxers, Boston terriers, and English bulldogs) are overrepresented among reported cases of can ine chemodectoma. Old male dogs are at greater risk of developing the condition. Tumors of the aortic body occur more often as single or mul tiple nodules in the pericardial sac near the base of the heart. Carot id body tumors arise near the bifurcation of the common carotid artery in the cranial cervical region. Clinical signs at presentation includ e signs of right-sided congestive heart failure (aortic body tumor) an d the presence of a neck mass (carotid body tumor). In the absence of necropsy, definitive diagnosis is usually based on exploratory surgery and histopathology of surgically excised tissue. Currently, early sur gical excision is the preferred treatment. Radiation therapy has been used in a limited number of cases. The prognosis for animals diagnosed with chemodectoma is guarded to fair.