Experimentally Induced Selenosis in Yellow-Bellied Slider Turtles ( Trachemys scripta scripta)

Selenosis, or selenium toxicosis, occurs in wildlife and livestock, usually because of excessive intake of selenium via selenium-containing plants. Although it is known that wild slider turtles can accumulate large amounts of selenium, little is known about how selenium exposure may affect these reptiles. In this study, the authors report histopathologic changes in yellow-bellied sliders ( Trachemys scripta scripta) caused by experimental exposure to selenomethionine. Microscopic changes in kidney and claw tissue were most significant and resembled those reported in birds. Turtles in the selenium treatment groups had acute tubular degeneration and regeneration in the kidney, with hyaline droplets in the high-dose animals, and changes in the claws ranging from epidermal hyperplasia with disorganization and intercellular edema to ulceration, and accumulation of seroheterophilic exudate between the epidermis and cornified layer. Although selenium burdens in this study are comparable with values found in wild slider turtles, more data are needed to determine if similar histopathologic abnormalities arise in wild animals exposed to high levels of selenium.