Anatomical Indicators of Dominance between the Coronary Arteries of Dogs

In humans, the right coronary artery is dominant. However, we did not find any citations in the literature concerning anatomical indicators of dominance among dogs. We used 30 hearts from mongrels of both sexes, fixed in 10% formalin. The branches of the coronary arteries were dissected with special attention to the levels that were considered to be reference points. In 96.7%, the circumflex branch of the left coronary artery reached or went beyond the crux cordis. The subsinuosus interventricular artery, ended before reaching the apex in 21 cases, at the apex in five cases and after the apex in four cases. The paraconal interventricular artery, ended before reaching the apex in two cases, at the apex in 11 cases and after the apex in 17 cases. The region of the heart apex was irrigated by branches of the left coronary artery, through the paraconal interventricular branch or through both of the interventricular branches. The mean length and number of ventricular branches of the left coronary artery were greater than those of the right coronary artery. The subsinuosus interventricular branch is a branch of the circumflex branch of the left coronary artery. In the hearts of dogs, the left coronary artery is dominant. The dominance pattern in dogs is different from the dominance pattern in human that is mentioned in the specialized literature.