Abstract

Trauma of undetermined cause resulted in the massive injury, resultant infection, and subsequent stranding of a juvenile green sea turtle, Chelonia mydas on 27 March 2001. With an initial total leukocyte count of <100 cells/:l and no mature heterophils seen on the peripheral blood smear, the turtle was treated with antibiotics and filgrastim (Neupogen), a recombinant human granulocyte colony-stimulating factor, in an attempt to increase heterophil production. Three daily doses of filgrastim at 6.4 mcg/kg given subcutaneously resulted in a rapid increase in proleukocytes, which subsequently declined over the next three days. A second regimen consisting of a repeat of the first three-dose daily regimen followed by continued dosing every 48 hr for an additional nine days maintained a white blood cell count of 10,000-17,000 cells/μl. Three weeks after initiating therapy, mature heterophils began to appear in the peripheral blood and the filgrastim was discontinued. Later, after the turtle was off all medications, a three-day regimen of filgrastim at 6.7 mcg/kg resulted in significant increases in total leukocytes, heterophils, lymphocytes, and monocytes. However, the leukocyte response was slower to occur and was less dramatic than during the first two regimens, presumably due to host antibody production. Finally, having regained normal body weight and recovered from its wounds and infections, the turtle was tagged and released on 30 November 2001. This case suggests that filgrastim may be effective in reversing leukopenia in green sea turtles when administered subcutaneously at 6.4-6.7 mcg/kg daily for three days then every other day until mature heterophils are observed. Clinicians are advised that the efficacy of filgrastim may decrease after extended treatment or after subsequent re-treatment in the reptilian patient.

Acknowledgments

The authors would like to acknowledge Don Thompson, Harbormaster, Burnt Store Marina, for notifying the turtle stranding network and Tracey Muller and Kathy Boucher from Mote Marine Laboratory, and Zoe Bass of Coastal Wildlife Club for the initial rescue and transport of the turtle. John Buck performed the microbiological analyses, for which we are grateful, and Judi Hartford's kind donation made this study possible. Finally, we wish to thank Jeannie Senn and the many Mote Animal Care Team volunteers for their daily efforts to save this turtle.