Pain and Pain Management in Sea Turtle and Herpetological Medicine: State of the Art.

In sea turtle rescue and rehabilitative medicine, many of the casualties suffer from occurrences that would be considered painful in other species; therefore, the use of analgesic drugs should be ethically mandatory to manage the pain and avoid its deleterious systemic effects to guarantee a rapid recovery and release. Nonetheless, pain assessment and management are particularly challenging in reptilians and chelonians. The available scientific literature demonstrates that, anatomically, biochemically, and physiologically, the central nervous system of reptiles and chelonians is to be considered functionally comparable to that of mammals albeit less sophisticated; therefore, reptiles can experience not only nociception but also "pain" in its definition of an unpleasant sensory and emotional experience. Hence, despite the necessity of appropriate pain management plans, the available literature on pain assessment and clinical efficacy of analgesic drugs currently in use (prevalently opioids and NSAIDs) is fragmented and suffers from some basic gaps or methodological bias that prevent a correct interpretation of the results. At present, the general understanding of the physiology of reptiles' pain and the possibility of its reasonable treatment is still in its infancy, considering the enormous amount of information still needed, and the use of analgesic drugs is still anecdotal or dangerously inferred from other species.

Pharmacokinetics of injectable marbofloxacin after intravenous and intramuscular administration in red-eared sliders (Trachemys scripta elegans).

Fluoroquinolone antibacterial drugs are currently used in reptilian medicine because of their broad spectrum of activity including the most frequent pathogens of these species. The disposition kinetics of marbofloxacin (MBX) at a single dose of 2 mg/kg were determined in healthy red-eared sliders after intravenous (IV) and intramuscular (IM) administration. The influence of renal portal system on the bioavailability of the drug was investigated by using forelimb and hindlimb as IM injection sites. Apparent volume of distribution at steady-state (Vss ) and systemic clearance (Cl) of marbofloxacin after IV administration were estimated to be 48.21 ± 5.42 ml/kg and 23.38 ± 2.90 ml/hr·kg, respectively. The absolute bioavailabilities after IM route were 45.96% (forelimb) and 52.09% (hindlimb). The lack of statistically significant differences in most of the pharmacokinetic parameters after the two IM injection sites suggests a negligible influence of renal portal system in clinical use of MBX, although the Cmax after IMfore administration is advantageous, having into account the concentration-dependent action of this antibiotic. The absence of visible adverse reactions in the animals and the advantageous pharmacokinetic properties suggest the possibility of its safe and effective clinical use in red-eared sliders.

Pharmacokinetic behavior of meloxicam in loggerhead sea turtles (Caretta caretta) after intramuscular and intravenous administration.

Data on reptile analgesia are scarce for nonsteroidal anti-inflammatory drugs (NSAIDs) and opioids and almost completely lacking in sea turtles, even though emergencies requiring correct pain management are very frequent in their rehabilitative medicine; therefore, dosage regimens extrapolated from other species involve the risk of clinical failure and damage to the animals. We describe the pharmacokinetic behavior of meloxicam in the loggerhead sea turtle (Caretta caretta). We chose meloxicam because of its selective anti-cyclooxygenase-2 activity and lesser adverse side effects. No data are available on the capacity of turtles to tolerate NSAIDs, so we chose a dose of 0.1 mg/kg of meloxicam. Plasma concentrations of meloxicam were unexpectedly low both for intravenous (IV; maximum concentration [C(max)] = 0.04±0.02 µg/mL) and intramuscular (IM; C(max) = 0.07±0.09 µg/mL) administration. A double-peak phenomenon occurred after both IV (time for second peak concentration T(max2) = 10.33±10.89 h) and IM (T(max2) = 1.17±0.75 h). The second peak after IM injection was premature, so some difficulty and delay in absorption appears to be an appropriate explanation. Furthermore, the area under the curve, and therefore systemic bioavailability (F = 31.82±28.24%), after both IV (0.30±0.29) and IM (0.10±0.03) injection appeared particularly limited. Terminal elimination slope and mean residence time indicated fast elimination after IM dosing; as a consequence, plasma concentrations dropped below analytic limits in 8 h. Considering that IM is the favored route of administration of drugs in rescue centers, it is unlikely that meloxicam at 0.1 mg/kg is an appropriate choice, particularly in long-term pain management protocols.

Surgical treatment of injuries caused by fishing gear in the intracoelomic digestive tract of sea turtles.

We report the surgical techniques used to remove accidentally ingested hooks and branchlines localized in different parts of the digestive tract of 129 loggerhead sea turtles Caretta caretta, together with the characteristics and localization of lesions, and final outcome related to their severity. Hooks were removed from the cervical esophagus via the ventral surface of the neck, while the supraplastron approach was performed for hooks wedged in the intracoelomic portion of the esophagus. An approach through the left axillary region was preferred for fishhooks in the stomach, while hooks and long branchlines in the intestine or pyloric area were removed by approaching the coelomic cavity through the right or left prefemoral fossa. The ingestion of fishhooks, and/or longlines, often induces severe injuries in the digestive tract that could lead to the death of the turtles, with the extent of damage engendered by lines often more severe than that caused by hooks, leading to strangulation, intussusception, and tears that require resection of long tracts of intestine. Spontaneous expulsion of hooks, even where possible, involves long waiting times, with the possible impairment of the turtle's clinical condition, and should be avoided when the line is evident or suspected. The development of diversified surgical techniques enabled us to approach the coelomic cavity with minimally invasive and easy-to-perform methods, and survival rates proved very satisfactory.

Diagnosis and treatment considerations in a case of malignant mesenchymoma in an African fur seal (Arctocephalus pusillus).

A 20-yr-old African fur seal (Arctocephalus pusillus) presented with a slowly growing mass located on the dorsum at the level of the last thoracic vertebrae. The mass was hard, 10 cm in diameter, and not adherent to the underlying tissues. Multiple biopsies were collected for histopathology and revealed extensive areas of necrosis, small nodules of malignant mesenchymal proliferation with areas of chondroid metaplasia, and atypical cells in vessel walls. The morphologic diagnosis was suggestive of malignant mesenchymal neoplasia originating from the vascular wall. The mass was removed 1 mo later due to ulceration and infection. Histologically, based on the World Health Organization's classification of neoplastic processes in domestic animals, the tumor was consistent with malignant mesenchymoma. The margins of resection revealed the presence of neoplastic cells. Based on these results, the particular species involved, the high local invasiveness, and the high metastatic index of this malignant tumor in domestic mammals and humans, the prognosis was poor. The animal died 6 mo later with metatastic disease.

Pharmacokinetics of marbofloxacin in loggerhead sea turtles (Caretta caretta) after single intravenous and intramuscular doses.

The disposition kinetics of marbofloxacin at a single dose of 2 mg/kg bodyweight were determined in a crossover trial with five clinically healthy loggerhead sea turtles (Caretta caretta) after i.v. and i.m. administration. Marbofloxacin plasma concentrations were determined by high-performance liquid chromatography (LOD/LOQ 0.05 microg/ml). Data were subjected to noncompartmental analysis. The integrated pharmacokinetic/pharmacodynamic variables showed that optimal area under the curve (AUC(0-24 h)): minimal inhibitory concentration (MIC) (>125) and Cmax: MIC (>8) ratios, as reported for concentration-dependent bactericidal antimicrobials (e.g., fluoroquinolones), were achievable with both a once daily i.v. or i.m. dose for microorganisms with MIC < or = 0.5 microg/ml, while a Cmax: MIC > 8 for MIC > or = 1 microg/ml was achievable only after the i.v. administration. The absence of adverse reactions in the animals after i.v. or i.m. administration of marbofloxacin and the favorable pharmacokinetic/pharmacodynamic properties after a single dose of 2 mg/kg suggest the possibility of its safe and effective clinical use in loggerhead sea turtles.

Pharmacokinetic behavior of enrofloxacin in estuarine crocodile (Crocodylus porosus) after single intravenous, intramuscular, and oral doses.

The disposition kinetics of enrofloxacin at a single dose of 5 mg/kg body weight were determined in clinically healthy captive-reared estuarine crocodiles (Crocodylus porosus) after intravenous (i.v.), intramuscular (i.m.), and oral (p.o.) administration. Enrofloxacin plasma concentrations were determined by diode array detection-high-performance liquid chromatography (limit of detection/limit of quantitation: 0.05 microg/ml). Data were subjected to noncompartmental analysis. The integrated pharmacokinetic-pharmacodynamic (PK-PD) variables showed that optimal area under the curve from the time of dosing to 24 hr:minimal inhibitory concentration (MIC) (>125) and peak plasma concentrations:MIC (>8) ratios, as reported for concentration-dependent bactericidal antimicrobials like fluoroquinolones, were achievable with both a single i.v. or i.m. dose for susceptible microorganisms with MIC values of < or =0.5 microg/ml, while the relatively slow onset of peak time allowed an effective plasma drug level only on day 3. The persistence of useful plasma concentrations indicated the possibility of redosing every 3 day for parenteral routes of administration, while further studies are needed for the oral route. Nevertheless, the absence of adverse reactions in the animals following i.v., i.m., or p.o. administration of enrofloxacin after a single dose of 5 mg/kg indicates the possibility of its safe and effective clinical use in captive estuarine crocodiles.

Reversible immobilization of asiatic black bear (Ursus thibetanus) with detomidine-tiletamine-zolazepam and atipamezole.

Chemical immobilization of free-ranging and captive wildlife is often required in many clinical situations. In this trial, tiletamine-zolazepam was combined with the alpha2-agonist, detomidine, in order to use the least amount of anesthetic drug possible to achieve a rapid immobilization; to ensure safety for animals and operators; and to be easily reversible with specific antagonists for a fast recovery. Twelve captive Asiatic black bears were anesthetized for clinical procedures, including clinical examination and blood sample collection, and for electrocardiographic and echocardiographic procedures. The combination detomidine-tiletamine-zolazepam, at the dosages of 0.03 mg/kg for detomidine and 1.5 mg/kg for tiletamine-zolazepam, proved to be reliable and effective in immobilizing Asiatic black bears for a 1-hr handling period for routine clinical procedures. Minimal or no respiratory and/or cardiopulmonary adverse side effects were observed, even with dosages calculated on the basis of an estimated body weight. The respiratory rate, pulse rate, and hemoglobin-oxygen saturation remained stable for the entire duration of anesthesia. Cardiac rhythm was always sinusal in all animals. Small injection volumes and darts for blowpipe use were utilized to minimize tissue damage at the site of injection. Induction and recovery were smooth and predictable, and provided for the safety of operators who could observe the bears' activities from a safe distance. Furthermore, the availability of the alpha2-antagonist atipamezole to counteract the effects of detomidine made this anesthetic regimen easily controllable and reversible. Moreover, the recovery time can be shortened by intravenous administration of this antagonist drug.

Monitoring of the endangered Pinna nobilis Linné, 1758 in the Mar Grande of Taranto (Ionian Sea, Italy).

The present study aimed to improve the knowledge of the bivalve Pinna nobilis L. population distribution in Mar Grande of Taranto (Ionian Sea). Although historical references report the local abundant presence of this endangered species, there is a lack of updated information about its exact distribution. For this purpose, a visual census of P. nobilis was performed by SCUBA diving in the Mar Grande basin from September 2004 to March 2005. Pinnids were found at depths from 3 to 16 m, with a density ranging from 0.1 to 0.7 ind ha(-1). The survey method employed in this study was non-destructive, relatively simple to perform and easily applicable for monitoring studies. Field data were stored in a database and linked with the study area by means of the GIS technology. The results of the present study indicate a tentative of recovery of P. nobilis population in Mar Grande in spite of all the difficulties of a degraded and heavily polluted environment and the damages of illegal fishing methods.