You Get Under My Skin: Cutaneous Trematode Infection and Treatment in Green Sea Turtles (Chelonia mydas)
Four green sea turtles (Chelonia mydas) in a managed care facility in the Virgin Islands presented with abnormal, wart-like proliferative skin lesions. These animals are housed in natural ocean water in rock sided bordered pools and have been there for over 17 years. Though several species of trematode have been reported in sea turtles in other nearby locales1, little research has been reported from our portion of the Caribbean; therefore, trematode infection was not immediately considered. Initially, many routine diagnostic results yielded no definitive etiology of the lesions. Multiple tests including skin scrapings, cytology of lesions, bacterial and fungal cultures and blood analyses were completed. Over the course of several months, these skin lesions increased in number, size and severity despite treatment with antibiotics, wound flushes, topical treatments and antiviral medications. Multiple true cut and punch biopsies of several lesions revealed proliferative disease with inflammation. Serology and PCR testing was performed for multiple viruses. Several repeat biopsies and sections of tissue were again evaluated and results identified migratory pathways of parasites. Further sections and analyses finally revealed the presence of trematodes. The animals were treated with praziquantel and some responses were poor with initial low normal doses, likely due to the toxins released and the high number of trematodes that died off. More debilitated turtles reacted poorly to published low end doses. These turtles received a lower dose for an extended time period. Once the parasites were eradicated, the turtles returned to normal status. During the time period of illness and treatment, the turtles' pools and water supply were evaluated and searched for sources of parasites as well as intermediate hosts. Multiple species of snails were found and eradicated from inline pipes and holding reservoirs to prevent future infection. This experience prompted us to implement a prophylactic treatment schedule for these turtles, as well as continue to monitor surrounding soil and ocean water reservoir for potential parasite hosts. This can assist to control invading parasites.
The authors wish to thank Dr. Michael Garner of Northwest Zoopath and Dr. Michael Kinsel of The Veterinary Diagnostic Laboratory at University of Illinois at Urbana-Champaign for processing, collaborating and diligence regarding samples from these patients.
* Presenting author
1. Stacy BA. Spirorchiid trematodes of sea turtles in Florida: associated-disease, diversity, and life cycle studies. [dissertation]. Gainesville, FL: University of Florida; 2008.