Sea Turtle Rehabilitation

Chapter 31 Sea Turtle Rehabilitation





Transport, History, and Physical Examination


Live stranded sea turtles should be confined in a sturdy container with foam padding and transported in a temperature-controlled vehicle to the closest rehabilitation facility. A thorough history, visual examination, and detailed systematic physical examination should be performed.23 Digital images may be used to document specific lesions or injuries. Body weight and standardized morphometric measurements should be obtained. A subjective and calculated body condition score (weight/carapace length [CL])3 should be recorded and then measured serially during rehabilitation. Deep cloacal temperature may be representative of the turtle’s recent environmental temperature and is an important parameter to obtain and monitor. A digital, distant laser, thermal monitoring device (Raynger ST, Raytek, Santa Cruz, Calif) directed at the prefemoral area correlates well with core body temperature. Heart rate and rhythm may be assessed with a Doppler probe placed on the skin between the distal cervical region and proximal front flipper. A standardized neurologic examination and workup should be performed if the patient exhibits neurologic signs.7




Nutrition in Critically Ill and Healthy Sea Turtles


The patient should be well hydrated, have a normal blood glucose level, and some evidence of active gastrointestinal tract (GIT) motility prior to starting oral nutritional support. Begin with smaller volumes and more dilute solutions and steadily increase both to meet the turtle’s nutritional requirements. Tube feeding may be a challenge in sea turtles. The volume of material accepted is usually less than predicted because gastric tubes often do not pass into the stomach, increasing the likelihood of regurgitation. A variety of feeding tube sizes and types are used, depending on the size of the turtle. Vegetable oil is used to lubricate the tube. The distance from the beak to the estimated anterior portion of the stomach should be marked on the tube. The patient is placed at a 45-degree incline on a padded board or held in this position in smaller patients to avoid regurgitation. The head and neck should be extended to straighten the esophagus for tube passage, with the head secured by grasping on either side behind the mandible. Steady downward pressure will cause the lower jaw to fatigue and open. A padded speculum is used to keep the mouth open. The turtle is held in this position after tube removal until it swallows to reduce the chances of regurgitation. To avoid possible inhalation, turtles may be placed back in the water to clear the oral cavity of any unwanted material. Esophagostomy tubes are used when necessary. Critical care products (Oxbow Pet Products, Murdock, Neb), fish-based gruels, Ensure (Abbott Laboratories, Abbott Park, Ill), Vital (Abbott), and Peptomen (Nestle Health Care Nutrition, Minnetonka, Minn) are used alone or in combination for tube feeding depending on the patient’s status. An experimental Mazuri tube feeding formula has been developed to replace fish gruels and has shown some promise. Although green turtles are herbivores, they may require a calorie-dense formula when emaciated. Formulas may be supplemented with glucose or honey to maintain adequate blood glucose levels and Pancreazyme (Virbac Animal Health, Fort Worth, Tex) to aid in digestion. Hyperalimentation has been used in selected cases.


Critically ill sea turtles may be fed filleted fish supplemented with calcium until they are defecating regularly. At first, high-protein, low-fat fish, such as smelt or capelin, are good choices; squid and clams take longer to digest and should be avoided initially. Fish may need to be cut into smaller pieces for smaller turtles. Bones, beaks, and chitinous materials may be slowly added back to the diet as the turtle starts defecating more regularly. Holding food in front of the nostrils may help in getting turtles to start eating. Emaciated green turtles may be fed predominantly seafood to improve body condition and then more dark green vegetables may slowly be added. Supplementing the diet with live and fresh-frozen natural prey items is important, especially prior to release back to the wild. Appropriate seafood storage, thawing, and handling protocols should be followed. A fish-based multivitamin containing thiamine (25 mg/kg of fish) and vitamin E (100 IU/kg of fish) should be provided daily. Iron supplementation should be provided and, ideally, based on plasma iron levels. General rules of thumb for the percentage of body weight in food to feed healthy sea turtles are hatchlings, 5%; yearlings, 1.5% to 3%; 2-year-olds, 1.5%; and then approximately 0.8% thereafter. Weight trends and body condition scores should be used for determining the amount to feed. Nutritionally complete gelatin diets are recommended for hatchlings being maintained in captivity for any length of time.23



Diagnostic Procedures


An emergency minimum database should consist of a hematocrit, total solids, glucose level and, subsequently, a complete blood count and plasma biochemical panel. A blood sample for culture should be collected before initiating antimicrobial therapy. We recommend taking up to 0.5 to 0.8 mL of blood/100 g body weight in healthy patients and a reduced sample volume for debilitated patients. Lithium or sodium heparin are the anticoagulants of choice, because ethylenediaminetetraacetic acid (EDTA) will cause red blood cell lysis. Plasma is preferred over serum because clot formation is unpredictable and may cause changes in the chemical composition of the sample and the higher volume of plasma obtained.


The preferred blood collection sites in most sea turtle species are the dorsal cervical or occipital sinus.32 The head and neck should be extended and difficult to bleed turtles (e.g., green turtles) may be positioned with the head directed in a ventral position. The lateral jugular vein is an alternative site for green turtles and the femoral and interdigital vessels are alternatives in leatherbacks.30 Lymph contamination may occur. Morphologic classification of blood cells6 and normal reference ranges for complete blood count, clinical chemistry, and plasma electrophoresis for the various sea turtle species have been reported.4,10,15,21 (See http://accstr.ufl.edu/blood_chem.htm for ongoing clinical pathology reference values.)


Radiography is an important diagnostic tool used to assess sea turtle patients. Radiopaque materials such as barnacles should be removed from the shell before performing a radiographic study. Anteroposterior and lateral projections using a horizontal x-ray beam and a dorsoventral (DV) view should be performed. Larger turtles may require multiple radiographs to assess the entire coelom from a DV view. Digestive tract radiographic contrast procedures are often necessary to document intestinal obstruction, motility disorders, and foreign bodies. Normal transit times have been established for barium sulfate and nonionic iodinate contrast media.11 Barium-impregnated polyethylene spheres may be placed in a food item, with subsequent serial radiography to assess gastrointestinal motility. Ultrasonography has been used to evaluate reproductive status and for general diagnostic purposes. Computed tomography (CT) is useful for assessing spinal and head injuries, free air pockets in the coelom, pneumonia, bronchiolar blockage, and internal fibropapillomatosis, although large sea turtles will not fit into most CT chambers. Normal skull CT anatomy has been established in loggerheads.2 Open magnetic resonance imaging (MRI) is useful for larger sea turtles and normal MRI internal anatomic structures have been established in loggerhead sea turtles.29 This technology has been used to detect internal fibropapillomas.9


Rigid endoscopy has been used for gender determination, evaluation of reproductive activity, exploring the coelomic cavity, organ biopsy for histopathology, and confirming the presence or absence of internal fibropapillomas. The technique has been described by Wyneken J, Mader DR, Weber ES, et al.32 Rigid and flexible endoscopy may be used to evaluate the cloaca, bladder, and distal GIT and to administer contrast media and enemas into the rectum. Rigid and flexible systems may be used to visualize the location of fish hooks in the esophagus. Flexible endoscopes may be used to evaluate the upper and lower GIT, trachea, bronchi, and anterior lung and for the removal of granulomatous material from the bronchial lumen.



Treatment


As noted, treatment of hypothermia, dehydration, hypoglycemia, and acid-base and electrolyte imbalances should be done in conjunction with starting other therapeutic agents. It is best to keep the sea turtle patient at its preferred optimal temperature zone while on therapy. Culture and sensitivity of various samples should be determined prior to starting antimicrobial therapy whenever possible. The front half of the body should be used for injections, especially when using nephrotoxic drugs. Anaerobic bacteria should be considered when deciding on a therapeutic plan. Several pharmacokinetic studies in sea turtles have significantly advanced treatment capabilities (Table 31-1).20,23


TABLE 31-1 Antimicrobials Used in Sea Turtle Patients























































Drug Dosage and Frequency Comments
Amikacin (A) 2.5-3.0 mg/kg IM q72h Targets primarily gram-negative bacteria, potentially nephrotoxic
Ceftazidime (C) 20 mg/kg* SC, IM, IV q72h22 Same as above but less nephrotoxic
Chloramphenicol 30-50 mg/kg IM q24h; 50 mg/kg PO q24h Bacteriostatic, aerobic, and anaerobic antibacterial spectrum
Clindamycin 5 mg/kg PO, IM q24h Anaerobic spectrum; use in combination with A, C, E
Enrofloxacin (E) 5 mg/kg SC/IM q 24-48h*;10-20 mg/kg PO q1wk20 Irritating to tissue; dilute when giving Sc
Metronidazole 20 mg/kg PO q24-48h Anaerobic bacteria, use with A, C, E
Fluconazole (F) 21-mg/kg loading dose,* then 10 mg/kg q5days SC, IV  
Intraconazole 5 mg/kg* PO SID or 15 mg/kg PO q72h Better choice than F for most common fungal species
Acyclovir 80 mg/kg PO SID Cutaneous herpesvirus, not FP
Fenbendazole 25 mg/kg SID × 3 days, repeat in 2 wk Bone marrow suppression
Pyrantel pamoate 10 mg/kg once, repeat in 2 wk  
Praziquantel 25 mg/kg* PO 3× in 1 day22 or SID × 3 days Use human form (Biltricide)

* Sea turtle pharmacokinetics.


Other reptiles.


Most sea turtles presented for emergency care are dehydrated. Hypoglycemia or hyperglycemia is common, so blood glucose determination is essential for choosing the appropriate fluid therapy. Most crystalloid fluids may be used in sea turtles23; however, overhydration is of particular concern in hypoproteinemic patients. Colloidal fluids may be more appropriate in these cases. Whole-blood transfusions using acid citrate dextrose are indicated in cases of acute hemorrhage and life-threatening anemia (5% or less). Fluid therapy, vitamin K, antibiotics, iron supplementation, and other supportive measures are often successful in less severe cases. A purified bovine hemoglobin (Oxyglobin, Dechra Veterinary Products, Overland Park, Kan) has had limited clinical use in sea turtles, with mixed results. Procrit (Epoetin AFA, Centocur Ortho Biotech, Horsham, Pa) has been used in conjunction with iron and nutritional support and has been helpful in treating non-regenerative anemias. Intravenous (IV) or intraosseous (IO) routes of fluid administration allow for rapid rehydration. Ultrasound is helpful for placing IV catheters. Bolus IV fluid therapy via the cervical sinus is often used for initial stabilization. The intracoelomic (IC) route via the inguinal fossa is commonly used for maintenance fluid therapy and allows for crystalloid fluids with up to 5% dextrose to be given. Subcutaneous fluids are placed in the inguinal fossa, medially in the front limb fossa and ventral neck fold. The oral route of fluid administration should be reserved for use in patients that are mildly dehydrated and maintenance fluid therapy. Placing the turtle in fresh water for 24 hours may be used for rehydration and reduction of epibiotic load. Maintenance fluid rates range from 10 to 25 mL/kg/day.

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Aug 27, 2016 | Posted by in EXOTIC, WILD, ZOO | Comments Off on Sea Turtle Rehabilitation

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