Abstract

Declines in eastern box turtles (Terrapene carolina carolina) have been reported from numerous locales throughout their range,^5,6 but the role of disease is unknown. Recently, mortality events in both amphibians and chelonians have implicated Ranavirus as the causative pathogen.^4,7 Regionally, ranaviral outbreaks have been reported in the southeast U.S. in chelonians and amphibians.^1,4-7

In 2007, whole blood samples were obtained from 40 wild eastern box turtles from a stable, well-studied population in east Tennessee. No evidence of Ranavirus infection was found using PCR. Forty-one injured or sick free-ranging eastern box turtles presented to the Veterinary Teaching Hospital at the University of Tennessee by good Samaritans and were also sampled. Whole blood, oral swabs, and/or necropsy tissues from (for those which died; n=10) were tested by PCR, and two animals were positive for Ranavirus. Histopathologic lesions consistent with Ranavirus infection were noted in only one PCR-negative animal. The overall prevalence, based on PCR and histopathology, was 10% (3/30). In the three positive cases, one was presented with clinical signs consistent with upper respiratory tract disease, one for trauma with no evidence of upper respiratory tract disease, and the third was a 5-g neonate with no clinical signs. The presence of this virus in a neonate may indicate vertical transmission. Further research is needed on the ecology of this disease in free-ranging turtles to establish the specific mechanisms and pathogenesis of disease in order to determine the effect on populations of threatened chelonians.

Literature Cited

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