Comparative cardiac morphology and macroscopic and microscopic pathological findings in cetaceans

Abstract

The coronary circulation, formed by the coronary arteries and veins, is responsible for supplying the heart. Belonging to the group of odontocetes, the bottlenose dolphin (Tursiops truncatus) presents a coronary circulation similar to other mammals, with certain characteristics such as the marked sinuosity of the coronary arteries as they course through the wall of the heart, the branching of the right coronary artery in the subsinusal interventricular branch, the multiple macroscopic interarterial anastomoses and the duplication of vessels in parallel branches. In cetaceans, different cardiac pathologies have been described on numerous occasions. In this retrospective study of cetaceans stranded between 2018/2019 in the Canary archipelago, which have been subjected to an anatomopathological study, the most common pathology refers to acute degenerative changes. These include contraction bands necrosis, wavy fibers, cardiomyocyte hypereosinophilia and cytoplasmic vacuolisation. Other cardiac pathologies, such as right ventricular hypertrophy, aortic dilatation, persistent ductus arteriosus, haemopericardium, endoarteriosis-endoarteritis, myocarditis and epicarditis, were also identified.