Exertional Myopathy in a Juvenile Green Sea Turtle (Chelonia mydas) Entangled in a Large Mesh Gillnet

Brianne E Phillips,Craig A Harms,Brian A Stacy,Matthew H Godfrey,Sarah A Cannizzo

doi:10.1155/2015/604320

Abstract

A juvenile female green sea turtle (Chelonia mydas) was found entangled in a large mesh gillnet in Pamlico Sound, NC, and was weak upon presentation for treatment. Blood gas analysis revealed severe metabolic acidosis and hyperlactatemia. Plasma biochemistry analysis showed elevated aspartate aminotransferase and creatine kinase, marked hypercalcemia, hyperphosphatemia, and hyperkalemia. Death occurred within 24 hours of presentation despite treatment with intravenous and subcutaneous fluids and sodium bicarbonate. Necropsy revealed multifocal to diffuse pallor of the superficial and deep pectoral muscles. Mild, multifocal, and acute myofiber necrosis was identified by histopathological examination. While histological changes in the examined muscle were modest, the acid-base, mineral, and electrolyte abnormalities were sufficiently severe to contribute to this animal’s mortality. Exertional myopathy in reptiles has not been well characterized. Sea turtle mortality resulting from forced submergence has been attributed to blood gas derangements and seawater aspiration; however, exertional myopathy may also be an important contributing factor. If possible, sea turtles subjected to incidental capture and entanglement that exhibit weakness or dull mentation should be clinically evaluated prior to release to minimize the risk of delayed mortality. Treatment with appropriate fluid therapy and supportive care may mitigate the effects of exertional myopathy in some cases.

Highlights

The green sea turtle (Chelonia mydas) is one of five sea turtle species that frequents the coastal waters of North Carolina, USA [1]
Exertional myopathy is characterized by various degrees of myocyte necrosis on histopathology, which occurs secondary to increased anaerobic metabolism and lactic acid production [22]
Metabolic acidosis is one of the predominant clinical pathology findings associated with exertional myopathy

Summary

Introduction

The green sea turtle (Chelonia mydas) is one of five sea turtle species that frequents the coastal waters of North Carolina, USA [1]. Incidental captures in fishing gear comprise a large part of North Carolina sea turtle stranding cases [2]. Greater duration of gillnet entanglement was associated with significant increases in plasma lactate, lactate dehydrogenase (LDH), creatine kinase (CK), and phosphorous levels in green sea turtles [17] These clinical pathology changes were suspected to be due to the exertion and muscle damage associated with entanglement, but the study lacked supporting evidence from blood gas analysis, gross postmortem examination, and histopathology. We present a case of exertional myopathy in a green sea turtle resulting from entanglement in a large mesh gillnet. Diagnostics included blood gas analysis, plasma biochemistry, gross necropsy, and histopathologic examination, which collectively are not typically available or presented in instances of sea turtle forced submergence and fishery interaction

Case Presentation

Findings

Discussion