Echocardiographic evaluation of four giant Aldabra tortoises (Aldabrachelys gigantea)

Abstract

ObjectivesIn recent years echocardiography has become a good diagnostic tool in Zoo Medicine but in some cases, it is still a challenge. In Aldabra giant tortoise (Aldabrachelys gigantea) the big size of animals and the few individuals hosted in Zoo are critical points for the application of this diagnostic technique.The purposes of this research were: to evaluate the feasibility of the diagnostic imaging technique on big-sized turtles; to define the echographic parameters for this species; and to describe the morphofunctional and physiological echographic characteristics of their cardiovascular system.DesignRepeated measures in vivo.SettingUltrasonography systematic description and Doppler analysis of the cardiovascular system of Aldabra giant tortoise were carried out; B-mode examination allowed the evaluation of the kinetics of the ventricle, the atria and the atrioventricular valves.Participants4 Aldabra giant tortoises (two adult males and two young females) hosted in two zoological gardens.InterventionsEchocardiography was performed placing the animals in ventral on a restraining platform raised from the floor, to provide adequate accessibility to the thoracic windows where the probe was placed. No chemical restraint was used.Primary and secondary outcome measuresHeart rate, systolic and diastolic areas and volumes, vessel diameters and blood flow velocity were measured.ResultsHeart rate was 21±4 bpm (range 14–25 bpm). The averages of the diastolic and systolic area indexes linked to the subject weight were: 21±3 cm2 and 9±1 cm2.The aortic annulus diameter in female specimens measured 11.2±0.8 mm, while it measured 21.5±0.3 mm in male species.ConclusionResults confirm the effectiveness of echocardiography as a means to study and evaluate the cardiovascular system of this species even if more studies on a bigger number of patients would be necessary to develop the echocardiography technique.

Determination of Echocardiographic Techniques for Clinical Assessment of Galapagos (Chelonoidis Nigra Complex) and Aldabra (Aldabrachelys Gigantea) Tortoises

“…Pericardial effusion has been suspected as both a pathologic and nonpathologic finding in previous studies of tortoises. 4,15,16 Based on this study and previous cases of heart diseases in tortoises, it is the opinion of the authors that a small amount of anechoic pericardial effusion is a physiologic finding in Galapagos and Aldabra tortoises.…”

“…The echocardiographic measurements collected in this study were similar to the four tortoises previously studied in similar age groups. 4 The information provided in this study can be used as a guide on how to perform echocardiograms in awake Galapagos or Aldabra tortoises.…”

“…3 and 4; Supplemental Videos 1-3). 4 The cervicobrachial window (left or right) was chosen dependent on a tortoise's willingness to allow access. The right cervicobrachial window was used by default.…”

“…A recent study provides a description of echocardiographic anatomy and function in captive Aldabra tortoises, but was limited to four tortoises. 4 The first objective of the current study was to establish and describe clinically relevant techniques for cardiac echocardiography in nonanesthetized Galapagos and Aldabra tortoises. The second objective was to establish guidelines for determining normal echocardiographic anatomy and function in both tortoise species.…”

Gross and Ultrasonographic Anatomy of the Coelomic Organs of Healthy Axolotls (Ambystoma Mexicanum)

“…44 In reptiles, pericardial effusion was initially considered an indicator of cardiac disease but is now increasingly documented as incidental in some species. 7,21,32,42 Ultrasound examination of reptiles and amphibians are frequently conducted under chemical or physical restraint. 2-4,6-8,13,21,27, 30,32,33,37,41,42 In this study, the ultrasonographic appearance of major coelomic organs was reported in conscious, unrestrained axolotls in ventral recumbency, thereby lessening the possible effects of stress, sedation, and physical compression of the coelomic organs.…”