Fibrosing cardiomyopathy is a significant cause of gorilla morbidity and mortality.1,2 A 33-year-old male lowland gorilla was conditioned through positive reinforcement to participate in transthoracic echocardiography on a twice-weekly basis. The gorilla had subtle signs of cardiac and respiratory insufficiency, including exercise intolerance. A specially designed PVC portal was installed in the cage wall that allowed the gorilla to place his thorax against the open end of the barred portal, permitting 2-D, M-mode and Doppler echocardiography. A standard 3.5-mHz convex linear-array probe was used with either a standard B-mode ultrasound unit (VFI-Ausonics Impact, Universal Ultrasound, Bedford Hills, NY), or digital ultrasound with color flow Doppler (MyLab 30-Universal Ultrasound). The right and left ventricles, mitral and tricuspid valves, pulmonary and aortic outflow tracts were fully imaged. Hepatic imaging demonstrated no evidence of passive congestion. Evidence of mural hyperechoic densities compatible with fibrosing cardiomyopathy were documented in the left and right myocardium and hyperechoic densities associated with the mitral valve were documented and monitored over a 1-year period. Due to significant areas of hyperechogenicity throughout the myocardium, and hyperechoic densities in the mitral valve leaflets, routine examination has been delayed. Routine ultrasound was performed to monitor the progress of cardiac health without the use of immobilizing drugs which may influence cardiac function. Use of behavioral restraint allowed for consistent evaluation of cardiac health in this gorilla and may serve as a model for consistently monitoring gorilla cardiac health.
1. Benirschke K, Adams FD. 1980. Gorilla diseases and causes of death. J. Reprod. Fert. Suppl. 28 (1980), 139–148.
2. Meehan TP, Lowenstine LJ. 1994. Causes of mortality in captive lowland gorillas: a survey of the SSP population. Proceedings of the American Association of Zoo Veterinarians Annual Conference, Pittsburgh, PA. Pp. 190–192.