Echocardiographic examination of 16 eastern grey kangaroos (Macropus giganteus) and one red kangaroo (Osphranter rufus)

Abstract

Habitat loss, road trauma, predation, disease, and natural disasters impact the health and survival of the family Macropodidae, including kangaroos. Cardiac disease has been reported, including hypertrophic cardiomyopathy (HCM), dilated cardiomyopathy (DCM), nutritional myodegeneration, valvular pathology, cardiovascular parasites, toxoplasmosis, and toxicities. Human research has evaluated macropod pericardium and aortic valves as possible bioprostheses. The goals of this prospective anatomic study were to echocardiographically evaluate opportunistically presented kangaroos: 14 clinically normal eastern grey kangaroos (EGK-Macropus giganteus), two sick EGKs, and one sick red kangaroo (RK, Osphranter rufus). Similar techniques as described in the dog were used. Standard B-mode images, M-mode mensuration, and Doppler measurements were attained; values were descriptively compared with published normal values. The clinically normal animals' M-mode values were similar to the closest weight-related kangaroo values. Most of the animals showed thicker-than-expected left ventricular and interventricular septal walls, and relative wall thickness (RWT) of 0.5 and 0.6; this may be the norm for macropods, but since an RWT>0.45 may indicate human HCM, this should be considered in the kangaroo. The sick animals were euthanized. Necropsy revealed highly suspect HCM in one EGK, and myxomatous mitral valve degeneration with suspect DCM in the other EGK and RK. In conclusion, there are weight-related similarities between previously published kangaroo values. More work is required on a larger number of weight and age cohorts of kangaroos. Subclinical HCM may be present in apparently normal animals. Findings can be used during clinical health assessments and for further research into macropod cardiac conditions.