Bleomycin is a Safe Drug for Focal Electrochemotherapeutic Treatment of Fibropapillomas in Green Turtles (Chelonia mydas)
2018 Joint EAZWV/AAZV/Leibniz-IZW Conference
Kyle Donnelly1*, DVM, MPH; Mark G. Papich2, DVM, MS, DACVCP; Anna Szivek3, DVM, DACVIM; Bette Zirkelbach4; Terry Norton5, DVM, DACZM; Brooke Burkhalter6, DVM; Joseph A. Impellizeri7, DVM, DACVIM, MRCVS; Nicole I. Stacy1, DVM, Dr. Med. Vet, DACVP
1Department of Comparative, Diagnostic, and Population Medicine, College of Veterinary Medicine, University of Florida, Gainesville, FL, USA; 2Department of Molecular Biomedical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, USA; 3Department of Small Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, Gainesville, FL, USA; 4,5,6The Turtle Hospital, Marathon, FL, USA; 5Georgia Sea Turtle Center/Jekyll Island Authority, Jekyll Island, GA, USA; 6Whitney Laboratory for Marine Bioscience, The Sea Turtle Hospital, St. Augustine, FL, USA; 7Veterinary Oncology Services, PLLC, Middletown, NY, USA
Fibropapillomatosis is a debilitating neoplastic disease of sea turtles with high prevalence in green turtles (Chelonia mydas). Treatment is generally centered on surgical extirpation of tumors and supportive care; however, these techniques can be associated with several complications including prolonged wound healing and recurrence. A new approach, electrochemotherapy, has recently been described in green turtles to avoid surgery and even general anesthesia.1 The objective of this study was to replicate the electrochemotherapy protocol from the previous report and add measurement of plasma bleomycin concentrations. Intralesional bleomycin was injected into two similarly sized tumors on two turtles at a dose of 0.5–1 U/cm3 of lesion after instillation of local anesthesia, followed by immediate electroporation. This treatment was repeated six weeks later. Plasma bleomycin concentrations of the main components (bleomycin A2 and B2) were measured by high-pressure liquid chromatography (HPLC) at 0, 1, 6, 12, 24, and 48 hours following each treatment. The concentrations of bleomycin A2 ranged from a peak of 0.35 µg/mL from the first treatment (0.5 mg injection) to 0.81 µg/mL from the second treatment (1.98 mg injection). Bleomycin appears to be reaching detectable plasma levels suggesting systemic circulation, but concentrations are very low compared to human procedures. By four months, the tumors were resolved and no healing complications or recurrence were encountered. This study adds further support that electrochemotherapy with bleomycin has the potential to be used as an effective alternative treatment for this complex disease process.
The authors wish to thank Richie Moretti, Caitlin Greene, and the entire staff of the Turtle Hospital for their excellent care of turtles and dedication to research. They also thank Ruth Francis-Floyd and the Whitney Lab for their support.
1. Brunner CHM, Dutra G, Silva CB, Silveira LMG, Monteiro Martins MdF. Electrochemotherapy for the treatment of fibropapillomas in Chelonia mydas. J Zoo Wildl Med. 2014;45:213–218.