ABSTRACT

Trauma of undetermined cause resulted in the massive injury, infection, and subsequent stranding of a juvenile green sea turtle, Chelonia mydas. With an initial calculated total leukocyte count of zero cells/μl and no mature circulating heterophils on the differential, the turtle was treated with antibiotics and recombinant human granulocyte colony-stimulating factor, (hG-CSF, filgrastim), in an attempt to increase heterophil production and possibly activation. Three daily doses o f hG-CSF at 6.7 mcg/kg given subcutaneously resulted in a rapid increase in acidophilic progranulocytes, 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 11,600 – 24,700 cells/μl. Three weeks after initiating therapy, mature heterophils began to appear in the peripheral blood and the hG-CSF was discontinued. Finally, after the turtle was off all medications, a three-day regimen of hG-CSF at 6.7 mcg/kg resulted in marked increases in total leukocytes, heterophils, lymphocytes, and monocytes. In this case human granulocyte colony-stimulating factor appeared to be effective in reversing severe leukopenia in a green sea turtle when administered subcutaneously at 6.4 – 6.7 mcg/kg daily for three days then every other day until mature heterophils were observed.