Reptile diagnostic endoscopy and endosurgery

Gastrointestinal Endoscopy

This review explores the application of gastrointestinal endoscopy in exotic animals, a field with unique challenges due to the diverse anatomic and physiologic characteristics of species such as small mammals, birds, reptiles, and amphibians. The study outlines its indications, including diagnostic and therapeutic purposes, and discusses the specific equipment and techniques required. Despite the technical difficulties and anesthesia risks associated with these procedures, gastrointestinal endoscopy remains a valuable tool in exotic animal medicine. Like in other diagnostic methods, the large number of species demands special knowledge of the anatomic characteristics.

Endoscopic techniques for early diagnosis of cloacal pathologies and sex determination in blue spotted tree monitor (Varanus macraei) and Cuming's water monitor (Varanus cumingi)

This article attempts to present, for the first time, the usefulness and feasibility of using endoscopic techniques in the cloacal region of Varanus cumingi and Varanus macraei. This method can serve both diagnostic and therapeutic purposes, as well as offering an early approach to sex determination through the observation of the urodeum which in males ends in a blind end while in females it consists of two ostia which represent the outlets of the oviducts. In this context, commonly employed sex determination techniques, such as post-cloacal spur detection, have shown unreliability. The study involved the examination of ten specimens, approximately one year old, from a private breeding farm, following a complete clinical evaluation to confirm their general state of health. All subjects underwent sedation, which allowed the evaluation of anatomical structures, the health status of the cloaca and the determination of sex. This study and its findings may provide a critical basis for addressing population declines of these species, particularly for V. macraei, which has already been classified as 'endangered' by the IUCN.

Husbandry Protocols for Juvenile Loggerhead Sea Turtles (Caretta caretta) Based on Stress Response to Stocking Density and Dry-Dock Time

When necessary, sea turtles are held captive for veterinarian care and research purposes. Protocols and basic guidelines have been described for husbandry of sea turtles with veterinarian needs but not considering physiological indicators of animal welfare. Because all sea turtle are imperiled species, monitoring their welfare is important. The aim of this study was to standardize husbandry protocols for loggerhead (Caretta caretta) juveniles held under seminatural conditions, based on circulating concentration of plasma corticosterone (Cort) and behavior. Two experiments were performed to analyze physiological and behavioral responses of the animals facing changes in stocking density and different dry-docking times. Cort analyses suggested that the number of animals per tank can be modified occasionally, without affecting their health and welfare. However, dry-docking time should be < 30 min, as indicated by the significant elevation of circulating Cort at ≥ 30 min, rising from 1.51- ng/ml to 5.28-ng/ml. Protocols tested did not affect behavioral responses, except for the breaths per move, which increased while Cort increased, despite differences exhibited by experimental animals in behavioral responses according to daily times (morning vs afternoon) and the sex of the animals.

Endoscopy and rectal enema for fecal collection in wild sea turtles (Chelonia mydas, Eretmochelys imbricata) in a field setting

Forty-seven free-ranging sea turtles (46- Chelonia mydas, 1- Eretmochelys imbricata) were examined via novel use of an endoscopy combined with a rectal enema to obtain large fecal sample volumes. The cloaca was insufflated using an endoscope, after which the bladder and rectum separated, allowing access to the colon. Environmental conditions and location influenced the performance of the procedure initially, but after several attempts the procedure was successfully initiated. In all cases, fecal samples were obtained, and the animals were released to their respective locations. Fecal sample collection using this approach enhances the ability to obtain diagnostic information and perform other scientific analyses of sea turtles.

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.

Diagnostic Imaging of the Reptile Urinary System

Reptiles can develop various diseases of the urinary tract, including, but not exclusively, urolithiasis, gout, acute and chronic kidney injury, and secondary renal hyperparathyroidism. Diagnostic imaging is instrumental in differentiating and diagnosing these ailments. This article describes the current diagnostic imaging approaches used in reptile medicine for evaluation of urinary tract disease. The use of radiographs, ultrasonography, computed tomography, MRI, and endoscopy is discussed and compared for the evaluation of urinary tract disease in reptiles.

Evaluation of diagnostic coelioscopy in koi (Cyprinus carpio)

OBJECTIVE To describe a technique for endoscopic evaluation of the coelomic viscera of koi (Cyprinus carpio) and to evaluate the ability to visually examine coelomic structures by use of an approach cranial or caudal to the pelvic girdle. ANIMALS 16 subadult koi. PROCEDURES Koi were anesthetized with buffered tricaine methanesulfonate. Coelioscopic examination was performed via a ventral midline incisional approach cranial or caudal to the pelvic girdle. A 2.7-mm × 18-cm 30° oblique endoscope within a 4.8-mm operating sheath and infusion of saline (0.9% NaCl) solution was used. Ease of entry into the coelomic cavity and visual examination of structures were scored for each fish. Fish were euthanized 2 or 8 weeks after the procedure, and necropsy was performed. RESULTS The coelioscopic procedure was tolerated well, and all koi recovered uneventfully. For all fish, ease of entry and visual examination scores of the liver, intestines, gonads, heart, and anterior kidney were satisfactory to excellent. Visual examination of the posterior kidney and swim bladder was satisfactory to difficult, whereas the spleen and gallbladder were not visually identified. No significant differences were noted in entry or visual examination scores between the cranial and caudal approaches or between sexes. Minor complications included mild hemorrhage, rupture of the gonadal capsule, formation of adhesions between the viscera and incision site, and delayed healing of the incision. CONCLUSIONS AND CLINICAL RELEVANCE Diagnostic coelioscopy of koi appeared to be safe and effective. This procedure could have potential for use in examination of coelomic structures and disease diagnosis.

Endoscopic assisted orchiectomy in Herman’s tortoises (Testudo hermanni sp.)

Objective: Male tortoises in captivity are often aggressive against other males or females, in particular during mating season related to hormonal influences (testosterone). Castration in males is the treatment of choice in many vertebrate species. A novel technique of minimal invasive castration is presented for Herman’s tortoises (Testudo hermanni).

Material and methods: The procedure was performed in ten mature males. An endoscope (2.7 mm/30° angled) was inserted into a prefemoral incision on each side. The testicle was resected after ligation of the gubernaculum testis and the spermatic cord using hemoclips.

Results: Each testicle could be removed in approximately 20 minutes. Complications like hemorrhage or damage of adjacent tissue did not occur and all animals recovered uneventfully.

Conclusions and clinical relevance: Using the bilateral prefemoral entrance offers an alternative option for orchiectomy in Herman’s tortoises without dissection of the shell. Thus complications like hemorrhage or impaired wound healing followed by sequestration of the bone flap are prevented. Because of the anatomical settings and the risk of tissue damage and time consumption, a unilateral approach is not recommended. Fasting the animals is necessary due to the voluminous gastrointestinal tract of this herbivorous tortoise and emptying the urinary bladder provides more space for manipulations in the coelomic cavity and prevents clipping and cutting of adjacent organs. The magnification via the endoscope is beneficial for orientation in the coelomic cavity, which is formed by the extremely convex carapace. Without this equipment it is challenging to visualize the dorsocaudally located gonads through the relatively small incision and the inserted instruments might block the view at the surgical field. Administration of hemoclips achieved a good hemostasis and the testicles could be resected without major blood loss. The described technique is a gentle method for resection of the testicles in this species and can be adapted to other European tortoise species of equal size.

Reproductive Medicine in Lizards

Common reproductive problems in captive male lizards are hemipenile plugs in hemipenial sac, unilateral prolapse of hemipenis, or bilateral prolapse of hemipene. Although the orchiectomy is performed as a treatment for testicular disease, the effectiveness in reducing aggressive behavior is unclear. Female captive lizards suffer from cloacal prolapse, preovulatory follicular stasis, or dystocia. The veterinarian must differentiate between the disorders because the treatment differs. Mating, physical, or visual contact with the male stimulates ovulation and prevents preovulatory follicular stasis. Surgical intervention is usually required for dystocia. This article discusses selected procedures and use of ultrasonography and diagnostic endoscopy.

Oncology of Reptiles: Diseases, Diagnosis, and Treatment

Based on necropsy review, neoplasia in reptiles has a comparable frequency to that of mammals and birds. Reptile neoplasia is now more frequently diagnosed in clinical practice based on increased use of advanced diagnostic techniques and improvements in reptilian husbandry allowing greater longevity of these species. This article reviews the current literature on neoplasia in reptiles, and focuses on advanced diagnostics and therapeutic options for reptilian patientssuffering neoplastic disease. Although most applied clinical reptile oncology is translated from dog and cat oncology, considerations specific to reptilian patients commonly encountered in clinical practice (turtles, tortoises, snakes, and lizards) are presented.

Coelioscopic and Endoscope-Assisted Sterilization of Chelonians

Elective sterilization is a safe and well-established surgical procedure performed in dogs and cats worldwide. Conversely, chelonian sterilization has been mostly performed therapeutically, because of the intricate anatomy and difficult access to the reproductive organs, and consequently, reproductive problems and diseases remain common. With the advance of veterinary endoscopy, novel techniques of soft tissue prefemoral coelioscopic and endoscope-assisted sterilization have been published, and preventative chelonian sterilization is now a reality. Nevertheless, extrapolations between species should be carefully considered, and further studies are warranted. This article summarizes and describes the current coelioscopic and coelioscope-assisted sterilization techniques for chelonia.

Clinical Applications of Cystoscopy in Chelonians

The medical approach to chelonians can be challenging. Cystoscopy may be useful to evaluate morphologic changes in the viscera without the need of celiotomy, and is a valuable diagnostic tool. The size and transparency of the urinary bladder in chelonians allows visualization of most coelomic organs. Through cystoscopy the external aspect of stomach, intestine, heart, lungs, liver, pancreas, spleen, kidneys, testes, and ovaries may be visualized. Although a definitive diagnosis cannot be achieved, rapid identification of the diseased system through cystoscopy may be possible. Furthermore, cystoscopy is fundamental for diagnosis and treatment of lower urogenital disorders.

Gender Identification by Cloacoscopy and Cystoscopy in Juvenile Chelonians

Cloacoscopy and cystoscopy are simple, noninvasive to minimally invasive techniques that provide excellent visualization, and result in fast recovery. General or intrathecal anesthesia is sufficient. They can be performed in free-ranging turtles under field conditions. Cloacoscopic gender identification of external genitalia is not reliable because of the high degree of misinterpretation between phallus and clitoris, especially in juveniles. However, saline-infusion or air insufflation cystoscopy through the urinary bladder (or accessory vesicles/bladders) is often effective for the visualization of gonads and to identify the sex. Visualization of gonads is feasible through the urinary bladder or accessory vesicle wall in many species.

Thoracoscopy in the cat: an up-and-coming diagnostic and therapeutic procedure

PRACTICAL RELEVANCE

Thoracoscopy provides a minimally invasive means of diagnosis and offers many important benefits when compared with open thoracotomy.

CLINICAL CHALLENGES

The expense of the equipment, the steep learning curve required to gain proficiency in thoracoscopic surgery, and the limitations imposed by the feline thoracic cavity, in terms of working and viewing space, are some of the challenges that have limited its uptake to date. However, it is envisaged that it will increase as a technique in feline medicine, in much the same way as laparoscopy has.

AUDIENCE

This article is directed at veterinarians currently performing open thoracic surgery and the associated aftercare who concurrently are adept at endoscopic surgery.

EVIDENCE BASE

The article draws on the small body of literature that is available on thoracoscopy in cats, which includes reports of its use for evaluation and management of undiagnosed pleural effusion, lung lobe torsion, persistent right aortic arch and chylothorax.

Endoscopically guided removal of cloacal calculi in three African spurred tortoises (Geochelone sulcata)

CASE DESCRIPTION

3 female African spurred tortoises (Geochelone sulcata) of various body weights (0.22, 0.77, and 2.86 kg [0.48, 1.69, and 6.29 lb]) were examined because of reduced food intake and lack of fecal output. Owners reported intermittent tenesmus in 2 of the tortoises.

CLINICAL FINDINGS

Physical examinations revealed no clinically important abnormalities in the tortoises. Cloacal calculi were diagnosed on the basis of radiography and cloacoscopy in all 3 tortoises. One tortoise had another calculus in the urinary bladder.

TREATMENT AND OUTCOME

Tortoises were anesthetized, and cloacal calculi were removed by use of a cutting burr (plain-fissure cutting burr and a soft tissue protector mounted to a dental handpiece that had a low-speed motor and a straight nose cone) and warm water irrigation with endoscopic guidance. Complete removal of calculus fragments was achieved by use of forceps and irrigation. In 1 tortoise, removal of the cloacal calculus was staged (2 separate procedures). In another tortoise, a second cloacal calculus (which had been located in the urinary bladder during the first examination) was successfully removed 25 days after removal of the first calculus. All 3 tortoises recovered uneventfully, and serious complications secondary to removal of the cloacal calculi were not detected.

CLINICAL RELEVANCE

Cloacoscopy combined with the use of a low-speed dental drill and warm water irrigation should be considered a simple, safe, and nontraumatic treatment option for removal of obstructive cloacal calculi in tortoises.

The chelonian respiratory system

This article reviews anatomy, physiology, diagnostic techniques, and specific disease syndromes of the chelonian respiratory system. Respiratory disease is common in chelonians and is a cause of significant morbidity and mortality in these animals. Mycoplasma, herpesvirus, and iridovirus are reviewed in depth.

Evaluation of diagnostic coelioscopy including liver and kidney biopsy in freshwater turtles (Trachemys scripta)

The objective of this study was to establish a safe and effective endoscopic technique for the examination of coelomic viscera and for the collection of liver and kidney biopsy specimens from turtles by use of a 2.7-mm rigid endoscopy system that is commonly available in zoologic veterinary practice. Twenty-two adult freshwater turtles (Trachemys scripta) were anesthetized for both left and right coelioscopic examinations. Ease of entry and organ visualization were scored, and liver and kidney biopsy specimens were collected from each turtle by use of 1.7-mm endoscopic biopsy forceps. Biopsy samples were evaluated histologically for quality and crush artifact. Five days after surgery, all turtles were euthanatized and underwent full necropsy examination. For all 22 turtles, left and right mean entry and visualization scores were satisfactory to excellent for all measured parameters except spleen because the spleen was impossible to locate from the left side. No iatrogenic trauma was evident, and biopsy specimens were consistent with tissues collected at necropsy. Liver biopsies suffered from greater crush artifact, compared with kidney biopsies. By use of a 2.7-mm rigid endoscopy system, coelioscopy, liver and kidney biopsy procedures can be performed safely, swiftly, and with ease in turtles. Biopsy specimens obtained by this technique are suitable for histologic examination. Endoscopy is recommended for the examination and biopsy of coelomic viscera in chelonians.