Abstract

Caryospora cheloniae is responsible for the most significant infectious epizootic documented in sea turtles.¹ Ponazuril and toltrazuril are triazinones that target the apicoplast, an organelle found in the phylum Apicomplexa.

Case 1 was a thin, lethargic juvenile Chelonia mydas with gas filled intestines. Supportive care was provided and buoyancy abnormalities resolved within 2 weeks. Although the turtle ate well, it continued to lose weight. Fecal examination revealed a moderate number of coccidia morphologically consistent with Caryospora cheloniae.^1,2 Consensus pan-coccidian PCR and sequencing of the 18S rRNA gene revealed it to be a member of the Eimeriidae most closely related to Eimeria arnyi and Eimeria ranae. Reference sequence for Caryospora cheloniae does not exist. Ponazuril was prescribed at 20 mg/kg orally q7days for four treatments. All fecal samples were negative 17 days after initiation of treatment. Fifteen days after discontinuing treatment, the turtle became anorexic. Blood chemistry revealed markedly elevated CK, AST, sodium, chloride, phosphorus, and uric acid. A muscle biopsy confirmed a mild granulomatous myositis devoid of infectious organisms. Pan-coccidian PCR of muscle was negative. After thirteen weeks of negative fecal samples and resolution of the post-treatment issues the turtle was released.

Case 2 was an eight kilogram Chelonia mydas with distended, gas filled intestines and traumatic carapace wound. Supportive care was provided, and buoyancy issues improved initially. Direct and flotation fecal analysis after 3 months found large numbers of coccidia morphologically consistent with Caryospora cheloniae.^1,2 Oral trimethroprim sulfa showed no effect on coccidian numbers after one month, and treatment was changed to Toltrazuril 10 mg/kg q7days for three treatments. No oocysts were detected and appetite/defecation are currently stable. Blood work was unremarkable during anti-coccidial treatment except for a persistent monocytosis and elevated magnesium. Currently the animal is free of coccidia but under treatment for positive buoyancy and a slight rise in creatine kinase (CK) and AST.

Triazinones are potential treatment options for green sea turtles. More research is needed on safety and efficacy of these drugs.

Acknowledgements

The authors wish to thank Mrs. Jackie Shum and staff of the Volusia County Marine Science Center and Kelly Thorvalson, Christi Hughes, Whitney Daniel, the volunteers of the South Carolina Sea rehabilitation turtle program for their dedication in caring for the turtles that undergo rehabilitation at our facilities. The authors thank Dr. Brian Stacy from the National Oceanographic and Atmospheric Science Administration and Dr. Ellis Greiner, Mr. Patrick Thompson and Ms. April Childress from the University of Florida School of Veterinary Medicine.

* Presenting author

Literature Cited

1.  Gordon, AN, Kelly, WR, Lester, RJG. 1993. Epizootic mortality of free-living green turtles, Chelonia mydas, due to coccidiosis. J Wildl Dis 29:490–494.

2.  Leibovitz, L, Rebell, G, Boucher, CG. 1978. Caryospora cheloniae sp. N.: A coccidial pathogen of mariculture-reared green sea turtles (Chelonia mydas mydas). JWildl Dis 14:269–275.