EN
Tumors of the heart constitute a slight percentage of all tumors in dogs. The most frequently occurring primary heart tumor is myxoma. Among cancerous tumors rabdomiosarcoma and chondromiosarcoma have been described relatively often. The most frequent localization is the base of the heart. In this article the authors describe a case of chemodectoma in a dog. This dog occasionally fainted and the cause of the loss of consciousness was paroxysmal vetricular tachycardia. A tumor at the base of the heart may have been the cause of the dog’s death, because it could have produced catecholamines. Catecholamines possibly induced ventricular tachycardia which was likely the cause of the sudden death of this dog.