Abstract

Abnormal buoyancy is a common presentation in ill and injured sea turtles and is also one of the more challenging clinical problems for reaching an accurate diagnosis and resolution. There is a wide range of etiologies that should be considered and differentiation of the conditions is further complicated by the need for enhanced diagnostic techniques to clarify an appropriate choice of therapy. Visual classification of buoyancy abnormalities is important for comparison and includes a number of presentations. The visual appearance of a buoyancy abnormality can give the clinician some clues as to its extent and potential etiology. Lateral asymmetry, with or without changes in head posture, may result from free coelomic air, a decreased lung volume unilaterally, an increased lung volume unilaterally associated with parenchymal disease or bronchiolar blockage, or an increase in intestinal gas. Symmetrical positive buoyancy may include coelomic air from pulmonary leaks due to trauma or infection, intestinal gas, lung hypertrophy, and the inability to compress otherwise normal lung tissue. Positive caudal buoyancy or ("bubble butt") animals are often associated spinal cord trauma though free air is not always present as may be expected.

Standard radiographic imaging can be very helpful if all views are analyzed but computerized tomography is more capable of determining the location and extent of abnormal air compartments as well as variations in pulmonary architecture. Freeware is available for 3D rendering which can help to clarify air cavities and lung morphology. Two useful programs are Osirix® for Mac users and Image J from NIH which can be downloaded for Mac and Windows users.

Products Cited

http://www.osirix-viewer.com

http://rsbweb.nih.gov/

Reference

1.  Schifino Valente AL. 2007. Diagnostic imaging of the loggerhead sea turtle, Caretta caretta Barcelona: University of Barcelona.