The Eastern box turtle (Terrapene carolina carolina) is threatened due to habitat loss, road mortality, and disease. Pathogens including ranavirus, Terrapene herpesvirus 1 (TerHV1), Mycoplasma sp., and adenovirus have been... [ view full abstract ]
The Eastern box turtle (Terrapene carolina carolina) is threatened due to habitat loss, road mortality, and disease. Pathogens including ranavirus, Terrapene herpesvirus 1 (TerHV1), Mycoplasma sp., and adenovirus have been recently identified in box turtles, and disease-related mortality events are increasingly reported in this species. Investigation of box turtle mortality events can provide valuable information for assessing disease impacts in this species. However, delayed recognition of mortality events, failure to collect appropriate diagnostic samples, and cost often limit mortality investigation. The objective of this presentation is to describe four box turtle mortality events observed in east central Illinois from 2011-2015. Mortality events were investigated as part of an ongoing health surveillance program utilizing physical examination, hematology, culture, necropsy, and qPCR testing. In April 2011, 53 recently deceased turtles were discovered. Of 12 live turtles evaluated, four (33%) were diagnosed with necrotizing bacterial infection. Common isolates included alpha Streptococcus sp., Aeromonas hydrophila, Corynebacterium sp., and Bacteroides sp. In summer 2013 – summer 2015, three ranavirus outbreaks involving 13, 10, and five turtles, respectively, were documented. Outbreak durations ranged from 10 to 27 days and ranavirus copy numbers ranged from 50 – 3.2x108. The prevalence of ranavirus (78%, p < 0.0001), Mycoplasma sp. (66%, p = 0.007), ranavirus and Mycoplasma sp. co-infection (44%, p=0.017) and heterophils (p=0.003) were significantly higher during the 2013 outbreak compared to post-outbreak turtles (N=13). Post-outbreak turtles had significantly fewer pathogens detected (p < 0.0001). In 2014, ranavirus prevalence (66%) and ranavirus co-infection prevalence (50%) were significantly higher during the outbreak compared to pre-outbreak (N=20; p = 0.005, p = 0.007) and post-outbreak turtles (N=5; p = 0.045, p = 0.048). These data provide a useful description of mortality events in free-living box turtles. Continued mortality research may improve our understanding of disease threats to box turtle conservation.
Topics: Infectious Disease , Topics: Disease Surveillance/Response , Topics: Reptiles
