Gender Identification by Cloacoscopy and Cystoscopy in Juvenile Chelonians

Sex Determination in Reptiles: A Review

Reptile biodiversity is rapidly declining, with over 11,733 recognized species across 1226 genera being documented, many of which are endangered. Captive breeding programs play a crucial role in conservation; however, effective management requires accurate sex determination, especially due to the fact that many reptile species exhibit minimal or no sexual dimorphism. When present, sexual dimorphism manifests as differences such as size, coloration, and morphological features influenced by evolutionary pressures and hormones. Various sex determination techniques are employed due to the lack of external sexual characteristics in many species. These methods include probing, hydrostatic eversion, popping, ultrasound, CT, radiography, contrast radiography, endoscopy, and genotypic sex determination. Accurate sex determination is crucial for the success of captive breeding programs and the conservation of reptile species. Advanced imaging and molecular methods offer promising non-invasive alternatives but may not be universally accessible or effective. An understanding of the unique reproductive anatomy and the use of appropriate sexing techniques are fundamental to establishing breeding groups, preventing aggressive behaviours among groups, and ensuring the long-term survival of endangered reptile populations.

Comparison of intramuscular alfaxalone with medetomidine-ketamine for inducing anaesthesia in Trachemys scripta spp. undergoing sterilization

OBJECTIVE

To compare the effect of two anaesthetic protocols on heart rate (HR), time to muscle relaxation and tracheal intubation and time to surgical plane of anaesthesia, in Trachemys scripta spp. undergoing oophorectomy.

STUDY DESIGN

Prospective randomized clinical study.

ANIMALS

A total of 43 healthy female turtles.

METHODS

Morphine (1.5 mg kg-1) was injected subcutaneously 2 hours before anaesthesia induction. The turtles were randomly administered either medetomidine (0.2 mg kg-1) and ketamine (10 mg kg-1) (group MK; n = 23) or alfaxalone (20 mg kg-1) (group A; n = 20) intramuscularly followed by bupivacaine (2 mg kg-1) administered subcutaneously along the incision site. Anaesthesia was maintained with isoflurane delivered in oxygen (100%). HR and the anaesthetic depth score (ADS) were recorded every 5 minutes from induction to recovery. A Friedman test followed by Wilcoxon tests with Bonferroni adjustment were used to compare these non-parametric data (HR and ADS) between groups and over time. Time to muscle relaxation of neck and limbs (TMR), tracheal tube insertion (TTTI) and stage of surgical anaesthesia (TADS≤3) were recorded and compared between groups using a Welch's t test after logarithmic transformation.

RESULTS

Median values of TMR, TTTI and TADS≤3 were 4, 9.5 and 25 minutes in group A, respectively, and 14, 20 and 35 minutes in group MK (TMR, TTTIp ≤ 0.0001; TADS≤3p = 0.001). Plane of anaesthesia was significantly deeper in group A than in group MK for the first 20 minutes (p < 0.01). HR at 10 and 15 minutes post injection was significantly lower in group MK (28 beats minute-1) than in group A (36 and 34 beats minute-1) (p < 0.02).

CONCLUSIONS AND CLINICAL RELEVANCE

After intramuscular injection in Trachemys scripta spp., tracheal intubation, muscle relaxation and a surgical plane of anaesthesia developed faster with alfaxalone than medetomidine-ketamine.

FIELD ANESTHESIA AND GONADAL MORPHOLOGY OF IMMATURE WESTERN SANTA CRUZ TORTOISES (CHELONOIDIS PORTERI)

Evaluation of sex ratios is a critical component of chelonian captive breeding programs and may become increasingly useful to assess the demographics of free-living populations. In many reptile species, the sex of immature animals cannot be determined based on external features. Endoscopic sex identification is an accurate and safe method to identify the sex of immature individuals of some chelonian species. A number of studies describe this technique in controlled, hospital settings and report significant interspecies variations in gonad morphology; however, there are few reports describing this technique in field conditions. In the current study, the gonadal morphology of 40 immature Western Santa Cruz tortoises (Chelonoidis porteri) on Santa Cruz Island in Galapagos, Ecuador, was assessed. A previously described endoscopic protocol was used to perform sex identification under field conditions. Tortoises were anesthetized using an intramuscular injection of ketamine (10 mg/kg) and medetomidine (0.1 mg/kg), which provided an adequate plane of anesthesia. The medetomidine was reversed with atipamezole (0.5 mg/kg). Field conditions presented challenges such as limited control over lighting, suboptimal patient positioning, and restricted power supply for endoscopy equipment. The immature testicle in Western Santa Cruz tortoises was oval, reddish pink, and tightly adhered to the coelomic membrane ventral to the kidney. The surface of the gonads resembled other species with the notable exception that the ovaries lacked a significant number of primordial follicles. These gonadal characteristics were consistent, with only one individual identified as undetermined sex of the 40 samples. This field-based endoscopic gonadal evaluation was a safe and sensitive technique for determining the sex of free-living immature Western Santa Cruz Galapagos tortoises.

Evaluation of a ventral and a left lateral approach to coelioscopy in bearded dragons (Pogona vitticeps)

OBJECTIVE

To compare a ventral and a left lateral endoscopic approach to coelioscopy in bearded dragons (Pogona vitticeps).

ANIMALS

18 adult bearded dragons.

PROCEDURES

In a randomized crossover design involving 2 surgical approaches, anesthetized bearded dragons first underwent coelioscopy with a ventral approach (left lateral of midline next to the umbilicus; animal positioned in dorsal recumbency) or left lateral approach (intercostal; animal positioned in right lateral recumbency) and then with the alternate approach. A 2.7-mm × 18-cm, 30° oblique telescope with a 4.8-mm operating sheath and CO₂ insufflation at 2 to 5 mm Hg were used. Ease of entry into the coelom and ease of visual examination of visceral structures were scored.

RESULTS

Both approaches were straightforward, with the left lateral approach requiring significantly more time than the ventral approach. Scores for ease of visual examination for the heart, lungs, liver, stomach, intestines, pancreas, gallbladder, left kidney, gonads, and fat body were good to excellent. Visual examination of the spleen and adrenal glands was difficult in most animals via either approach. The left kidney, testis, and vas deferens were easier to see with the left lateral approach, whereas the pancreas in females and gallbladder in both sexes were easier to see with the ventral approach. All bearded dragons recovered without complications from the procedures, except for one with nephritis, renal gout, and hepatic necrosis.

CONCLUSIONS AND CLINICAL RELEVANCE

Both coelioscopy approaches could be safely and effectively used in bearded dragons. Choice of approach should be based on the coelomic structures requiring evaluation.

Reproductive Medicine in Freshwater Turtles and Land Tortoises

Chelonian reproductive medicine is an extremely important facet to ensuring captive populations for the pet trade and conservation efforts around the globe. This article covers basic chelonian reproductive anatomy and physiology, natural history, behavior, and sexing chelonians, in addition to discussing reproductive disorders that are commonly seen by veterinarians. Reproductive disorders covered include infertility, dystocia, follicular stasis, egg yolk coelomitis, phallus prolapse, and reproductive neoplasia. It is hoped that this information will allow clinicians to recognize, understand, and successfully treat reproductive disorders in chelonians, thus providing the best available care for our chelonian patients.

Reproductive Disorders and Perinatology of Sea Turtles

Sea turtles' reproductive disorders are underdiagnosed, but potentially, there are several diseases that may affect gonads, genitalia, and annexes. Viruses, bacteria, and parasites may cause countless disorders, but more frequently the cause is traumatic or linked to human activities. Furthermore, veterinary management of the nest is of paramount importance as well as the care of newborns (also in captivity). This article gives an overview on the methods used to manage nests and reproductive activities of these endangered chelonians species.

Reptile Perinatology

Reptile perinatology refers to the time period surrounding hatching for oviparous species, and immediately after birth for viviparous species. Veterinarians working in myriad conservation and breeding programs require knowledge in this area. This article reviews anatomy and physiology of the amniotic egg, the basics of artificial incubation, when manual pipping is indicated, and basic medicine of the reptile hatchling or neonate.

Description of cloacoscopy in the loggerhead sea turtle (Caretta caretta)

The aim of the study was to describe cloacoscopy in the loggerhead turtle (Caretta caretta) and to evaluate its efficacy in clinical practice. Cloacoscopy was performed on 31 turtles, 23 females and 8 males. Thirty minutes before anaesthesia, meloxicam (0.4 mg/kg) was administered intramuscularly. Turtles were anaesthetised with a combination of 0.04 mg/kg dexmedetomidine and 4 mg/kg ketamine administered intramuscularly. Cloacoscopy was performed with a diagnostic telescope (10 mm diameter, 30 cm long, 0°, with an operating sheath) or with a flexible colonoscope (13 mm diameter, 160 cm long). Turtles were placed in dorsal recumbence and endoscope was inserted through the vent. In the distal part of the proctodeum, phallus or clitoris were easily visualized. A finger and thumb were placed around the vent to act as a valve in order to control the fluid infusion. Flushing the cloaca with warm saline and 0.6% lidocaine allowed clear view. The urethral orifice was located centrally within the urogenital sinus. Further proximally, the slit of the urodeum with the distal sphincter of the colon could be visualized. Passing gently through the urethral orifice allowed direct visualization of the urinary bladder. After withdrawing and re-directing the endoscope into the coprodeum, the terminal part of the intestine was reached. From 31 loggerhead turtles examined, fishing lines were found in 23 animals. Cloacoscopy proved to be a feasible diagnostic method and it is suggested as a routine diagnostic tool for clinical assessment of loggerhead turtle patients.