qraphy is based upon the use of water soluble iodinated contrast 

 agents. These agents are administered parenterally, excreted 

 almost exclusively by goloerular filtration, not resorbed by the 

 tubules, and concentrated by the normal solute and water 

 resorbing processes of the kidney, thereby providing radiographic 

 contrast in the kidney due to the high density of iodine within 

 it, i.e., the kidneys can be seen on radiographs, a process known 

 radiographically as opacification (Witten et al., 1980). 



The opacification technique is a well-known and widely-used 

 radiologic procedure in humans (Witten et al., 1980) as well as 

 in some animal species such as the dog and cat (Gillette, 1977) . 

 It has been attempted in birds but has not been successful 

 (Altman, 1978) . The preferred route of administration of contrast 

 is intravenous. However intravenous access in small turtles, 

 although possible, is not always successful or satisfactory, 

 (Fry, 1978) . Therefore, a repeatable, satisfactory and safe 

 means of administration with reproducible results is needed. 



Cernv and associates, in a two-phase study using sodium 

 diatrizoate in rabbits, demonstrated that the subcutaneous admi- 

 nistration of contrast material produced satisfactory results as 

 well as an acceptable level of side effects and minimal tissue 

 injury (Cerny et al., 1967). Afterward they obtained satisfac- 

 tory excretory urograms in 98 of 100 human patients with sub- 

 cutaneous injections, while minimal side effects and no tissue 

 slough were observed. Further, sodium diatrizoate and similar 

 compounds have little observed toxicity in animals (Gillette, 

 1977) . Since the subcutaneous method of administration is a 

 recognized safe alternative to intravenous injection, it was cho- 

 sen for this study. 



In a preliminary studv to opacify the kidneys in two 



