Quimiodectoma em cão / Chemodectoma in a dog

ABSTRACT

Background: The chemodectoma is a rare neoplasm that originates from chemoreceptors located mainly in the aortic body,and carotid body and sinus, and responsible for detecting variations in blood pH, oxygen pressure and carbon dioxide. Dogsof brachiocephalic breeds and aged between 7 and 15 years have greater propensity. A neoplasm involves infiltrative growthin the vessels at the heart base, which leads to Congestive Heart Failure (CHF). The definitive diagnosis is performed byhistopathological and/or immunohistochemical examination. The aim was to report a case of chemiodectoma in a dog,showing the disease’s clinical characteristics.Case A 13-year-old male undefined breed dog was examinated in the medical clinic of small animal of Veterinary Hospital,Federal Rural University of Pernambuco (UFRPE) with respiratory effort, hyporexia, and edema in face, cervical, ventralthorax and thoracic limbs, with thirty days evoluted. About physical examination, we observed cachexia, orthopneic position, cyanosis and edema with a positive Godet sign, as well as 8% dehydration degree. Thoracic auscultation presentedmixed dyspnea and muffled heart sounds. Chest radiography detected an radiopacity increase in pulmonary section andmetastatic neoplastic process associated with pleural and pericardial effusion. Fluid therapy with lactated ringer and posteriorthoracentesis in the right hemithorax region was performed for greater respiratory comfort for the patient. Hematologicalcount and biochemical profiles stated normochromic normocytic anemia, relative and absolute lymphopenia, thrombocytopenia, as well as increased alanine aminotransferase (ALT) and aspartate aminotransferase (AST). The patient diedafter 12 hours when was submitted to necroscopic examination and histopathological evaluation. An infiltrative tumor ofcardiac base was observed invading the light of the right atrium, obstructing the venous return, as well as a large thrombus...