Abstract

Fibropapillomatosis (FP), a neoplastic disease of sea turtles with a likely primary herpesviral etiology, is characterized by variable numbers of cutaneous, conjunctival, and occasionally visceral growths.^5,6 Over the past three decades, FP has emerged as an important disease in green sea turtles (Chelonia mydas), and has reached epizootic proportions in several locations.^3,4,8 We characterized and statistically evaluated the occurrence, clinical presentation, case progression, and outcome of sea turtles with FP at a rehabilitation facility, the Georgia Sea Turtle Center, Jekyll Island, GA (GSTC). As a control group, we also evaluated case data from an equivalent set of non-FP rehabilitating turtles. Tumor scores (0–3) were assigned to all patients according to size, number, and location.⁹ During 2009–2012, FP was present in ~ 5% (n = 18) of rehabilitating sea turtles at the GSTC, including green (Chelonia mydas) and Kemp's ridley (Lepidochelys kempii) turtles. The majority of the turtles with FP (FP+) were juvenile (94.4%),¹ female (87.5%), green (94.4%) sea turtles. Most of these cases (61.1%) were found along the Florida coast; 38.7% were found in Georgia. Proportions of strandings of FP+ cases did not significantly differ by season (warm/cool) or month. Neither straight carapace length nor weight differed significantly between FP+ and control cases. Highest FP prevalence was in the 25–29.9 cm and 40–44.9 cm SCL size classes (22.2% each). Odds ratios analysis showed that two sources of co-morbidity, floating and emaciation, were significantly more likely to be observed in FP+ turtles than in non-FP turtles. Average time in rehabilitation was 251 days (± SE 18.94) for FP+ turtles, and 127 days (± SE 62.59) for non-FP turtles. Time to FP onset ranged in weeks from 0 (44.4%); to 1–10 (27.8%); to 11–20 (5.6%); to 31–40 (22.2%). Blood parameter abnormalities observed concurrent with peak FP severity include anemia (33.3%); monocytosis and eosinophilia (27.8% each); increased creatine kinase (38.9%); hyperphosphatemia (33.3%); hypoproteinemia (27.8%); hypocalcemia (22.2%); and hypoalbuminemia (16.7%).² Discriminant function analysis of blood parameters suggests that turtles can be classified into groups (FP+ vs. non-FP) by blood parameters tested on the day of admission into the GSTC, but not during peak tumor severity.⁷ We related clinical pathology parameters to tumor scores, using means and standard errors of blood parameter values.⁹ Of the FP+ cases, the following outcomes were seen: 61.1% were released following rehabilitation (22.2% released with mild cutaneous FP; 38.9% released tumor-free); 22.2% were euthanized due to FP; 11.1% died in captivity; and 5.6% (i.e., one turtle) lives in permanent captivity. Odds ratio analysis of FP presence/absence and case outcome (released vs. euthanized) revealed that FP+ turtles had significantly greater odds of being euthanized than non-FP turtles. All euthanized FP+ turtles had a peak tumor score 3; all released FP+ turtles had a peak tumor score 1 or 2. These results provide a logical summary of the multifactorial aspects of FP cases in rehabilitation, suggest important parameters to evaluate in prospective FP cases, and provide potential predictors for possible case outcomes.

Acknowledgements

The authors wish to thank the University of Georgia, College of Veterinary Medicine, for financial and interdisciplinary support. Dr. Page-Karjian was supported by a Ph.D. Scholars of Excellence Graduate School Assistantship award. The authors thank the Georgia Sea Turtle Center staff for technical assistance.

* Presenting author
+ Student presenter

Literature Cited

1.  Bresette MJ, Witherington BE, Herren RM, Bagley DA, Gorham JC, Traxler SL, Crady CK, Hardy R. 2010. Size-class partitioning and herding in a foraging group of green turtles Chelonia mydas. Endanger Species Res 9:105–116.

2.  Campbell TW. 2006. Clinical Pathology of Reptiles. In: Mader DR, editor. Reptile Medicine and Surgery, 2nd Ed., Philadelphia (PA): WB Saunders Co. p. 453–470.

3.  Chaloupka M, Balazs GH, Work TM. 2009. Rise and fall over 26 years of a marine epizootic in Hawaiian green turtles. J Wildl Dis 45:1138–1142.

4.  Foley AM, Schroeder BA, Redlow AE, Fick-Child KJ, Teas WG. 2005. Fibropapillomatosis in stranded green turtles (Chelonia mydas) from the eastern United States (1980–98): Trends and associations with environmental factors. J Wildl Dis 41:29–41.

5.  Herbst LH. 1994. Fibropapillomatosis of marine turtles. Ann Rev Fish Dis 4:389–425.

6.  Herbst LH, Jacobson ER, Klein PA, Balazs GH, Moretti R, Brown T, Sundberg JP. 1999. Comparative pathology and pathogenesis of spontaneous and experimentally induced fibropapillomas of green turtles (Chelonia mydas). Vet Pathol 36:551–564.

7.  Swimmer JY. 2000. Biochemical responses to fibropapilloma and captivity in the green turtle. J. Wildl Dis 36:102–110.

8.  Williams EH, Bunkley-Willams L. 1994. An epizootic of cutaneous fibropapillomas in green turtles Chelonia mydas of the Caribbean: Part of a panzootic? J Aquat An Health 6:70–78.

9.  Work TM, Balazs GH. 1999. Relating tumor score to hematology in green turtles with fibropapillomatosis. J Wildl Dis 35:804–807.