RETROSPECTIVE REVIEW OF HISTOLOGIC FINDINGS IN CAPTIVE GILA MONSTERS (HELODERMA SUSPECTUM) AND BEADED LIZARDS (HELODERMA HORRIDUM).

A retrospective study was performed by reviewing all Heloderma spp. submissions to Northwest ZooPath from 1996 to 2019. Necropsy and biopsy specimens from 106 captive Gila monsters (Heloderma suspectum) and 49 captive beaded lizards (Heloderma horridum) were reviewed. Inflammatory diseases were the most frequently diagnosed condition in Heloderma spp., and were diagnosed in 72% of all animals examined, including 76% of Gila monsters and 63% of beaded lizards. The most common cause of inflammation was bacterial infection, which was present in 52% of all Heloderma spp. with inflammation. Enterocolitis was common in Gila monsters (20%) and beaded lizards (14%), but the underlying causes were different for each species. Cryptosporidium spp. was the most common cause of enterocolitis in Gila monsters (36%) but was not identified in beaded lizards. Amoebiasis was a common cause of enterocolitis in Gila monsters (27%) and was the most common cause of enterocolitis in beaded lizards (57%). Deposition diseases were diagnosed in 34% of all Heloderma spp. The most frequently diagnosed deposition disease in beaded lizards was urolithiasis-nephrolithiasis (12%). This disease was not diagnosed in Gila monsters. Deposition diseases that were common in Gila monsters and beaded lizards included hepatic lipidosis and renal gout. Neoplasia was diagnosed in 17% of all Heloderma spp., including 17% of Gila monsters and 18% of beaded lizards. The most common neoplasm of Heloderma spp. was renal adenocarcinoma, which was equally common in Gila monsters and beaded lizards. Less common diagnoses included degenerative diseases, trauma, nutritional disease, nonneoplastic proliferative disease, nondegenerative cardiovascular disease, and congenital malformation.

A fixed moderate-dose combination of tiletamine+zolazepam outperforms midazolam in induction of short-term immobilization of ball pythons (Python regius).

Laboratory animals are commonly anesthetized to prevent pain and distress and to provide safe handling. Anesthesia procedures are well-developed for common laboratory mammals, but not as well established in reptiles. We assessed the performance of intramuscularly injected tiletamine (dissociative anesthetic) and zolazepam (benzodiazepine sedative) in fixed combination (2 mg/kg and 3 mg/kg) in comparison to 2 mg/kg of midazolam (benzodiazepine sedative) in ball pythons (Python regius). We measured heart and respiratory rates and quantified induction parameters (i.e., time to loss of righting reflex, time to loss of withdrawal reflex) and recovery parameters (i.e., time to regain righting reflex, withdrawal reflex, normal behavior). Mild decreases in heart and respiratory rates (median decrease of <10 beats per minute and <5 breaths per minute) were observed for most time points among all three anesthetic dose groups. No statistically significant difference between the median time to loss of righting reflex was observed among animals of any group (p = 0.783). However, the withdrawal reflex was lost in all snakes receiving 3mg/kg of tiletamine+zolazepam but not in all animals of the other two groups (p = 0.0004). In addition, the time for animals to regain the righting reflex and resume normal behavior was longer in the drug combination dose groups compared to the midazolam group (p = 0.0055). Our results indicate that midazolam is an adequate sedative for ball pythons but does not suffice to achieve reliable immobilization or anesthesia, whereas tiletamine+zolazepam achieves short-term anesthesia in a dose-dependent manner.

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.

An endoscopic method for identifying sex of hatchling Chinese box turtles and comparison of general versus local anesthesia for coelioscopy.

OBJECTIVE: To establish a safe and effective endoscopic method for visualizing the gonads and identifying the sex of hatchling Chinese box turtles and to compare the effects of general versus local anesthesia during coelioscopy. DESIGN: Clinical trial. ANIMALS: 58 hatchling Chinese box turtles (Cuora flavomarginata). PROCEDURES: Turtles were randomly assigned to be anesthetized with a mixture of ketamine, medetomidine, and morphine (n = 29) or to receive local anesthesia with lidocaine in the prefemoral region (29). Coelioscopy was performed with a rigid 1.9- or 2.7-mm telescope following insufflation with sterile lactated Ringer's solution. Ease of endoscopic sex identification and quality of anesthesia were scored. Body weights were recorded before and 7 and 14 days after surgery. RESULTS: Gonads were easily visualized and sex was easily identified in all 58 turtles without complications. Endoscopy scores and pre- and postoperative weights did not differ significantly between groups. However, anesthesia scores were significantly worse for animals that received local anesthesia alone, compared with those that underwent general anesthesia. All anesthetized turtles recovered within 21 minutes after administration of the reversal agents, atipamezole and naloxone. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that coelioscopy with a rigid endoscope and lactated Ringer's solution for insufflation was a safe and effective method for identifying the sex of hatchling Chinese box turtles. General anesthesia was effective and effects were rapidly reversible; local anesthesia with lidocaine alone was considered insufficient for coelioscopy.

Comparison between CO2 laser and 4.0 MHz radiosurgery for incising skin in white Carneau pigeons (Columba livia).

To objectively evaluate the collateral damage associated with radiosurgical and carbon dioxide (CO2) laser devices, a comparative surgical and histologic study was undertaken in white Carneau pigeons (Columba livia). Ten pigeons were anesthetized, and a series of 3 skin incisions were made in the pectoral region by using a 4.0-MHz radiosurgical unit, a CO2 laser, and a scalpel blade (control). A total of 90 skin incisions were microscopically evaluated, and their associated mechanical- and thermal-induced tissue lesions were measured in micrometers. Scalpel incisions invariably resulted in hemorrhage, whereas all laser and radiosurgical skin incisions were essentially bloodless. Scalpel blade incisions were least traumatic (mean [SD] 18 +/- 15 microm) followed by incisions created with radiosurgery (mean [SD] 94 +/- 60 microm) and CO2 laser (mean [SD] 150 +/- 64 microm). Radiosurgery was significantly less traumatic than CO2 laser (P = .003). Radiosurgery appears to offer significant benefits over CO2 laser for avian surgery.

Evaluation of transcutaneous pulmonoscopy for examination and biopsy of the lungs of ball pythons and determination of preferred biopsy specimen handling and fixation procedures.

OBJECTIVE: To establish a safe and effective technique for the endoscopic examination and biopsy of snake lungs by use of a 2.7-mm rigid endoscope system. DESIGN: Clinical trial. ANIMALS: 17 adult ball pythons (Python regius). PROCEDURES: The right lung of each anesthetized snake was transcutaneously penetrated at a predetermined site. Endoscopic lung examination was objectively scored, and 3 lung biopsies were performed. Tissue samples were evaluated histologically for diagnostic quality. One year later, 11 of the 17 snakes again underwent pulmonoscopy and biopsy; specimens were placed in various fixatives to compare preservation quality. All 17 snakes were euthanatized and necropsied. RESULTS: No major anesthetic, surgical, or biopsy-associated complications were detected in any snake. In 16 of 17 pythons, ease of right lung entry was satisfactory to excellent, and views of the distal portion of the trachea; primary bronchus; intrapulmonary bronchus; cranial lung lobe; and faveolar, semisaccular, and saccular lung regions were considered excellent. In 1 snake, mild hemorrhage caused minor procedural difficulties. After 1 year, pulmonoscopy revealed healing of the previous transcutaneous lung entry and biopsy sites. Important procedure-induced abnormalities were not detected at necropsy. Diagnostic quality of specimens that were shaken from biopsy forceps into physiologic saline (0.9% NaCl) solution before fixation in 2% glutaraldehyde or neutral-buffered 10% formalin was considered good to excellent. CONCLUSIONS AND CLINICAL RELEVANCE: By use of a 2.7-mm rigid endoscope, lung examination and biopsy can be performed safely, swiftly, and with ease in ball pythons. Biopsy specimens obtained during this procedure are suitable for histologic examination.

Endoscopic orchidectomy and salpingohysterectomy of pigeons (Columba livia): an avian model for minimally invasive endosurgery.

To evaluate a minimally invasive endosurgical system in birds, endoscopic orchidectomy and salpingohysterectomy were evaluated in 11 male and 14 female pigeons (Columba livia). Anesthesia was maintained by using isoflurane delivered by a pressure-cycle ventilator and produced good to excellent anesthesia during 96% of procedures. Endosurgery was performed with a 2.7-mm telescope system, 3-mm human pediatric laparoscopy instruments, and a 4.0-MHz radiofrequency device. Mean +/- SD surgery times for bilateral orchidectomy and salpingohysterectomy procedures were 39 +/- 18 minutes and 34 +/- 15 minutes, respectively. Procedures were generally straightforward, with any minor complications easily overcome. Surgical complications were generally minor, with mild hemorrhage and focal coagulative damage to the kidney being most common. All pigeons recovered quickly (20 +/- 11 minutes), with 95% displaying good to excellent recoveries. No birds exhibited any clinically apparent morbidity or mortality associated with endosurgery. At least 1 male and 1 female bird were subjected to elective euthanasia and necropsy on postoperative days 1, 3, 5, 10, 20, and 90 to determine the success and side effects of surgery. Gross and histologic abnormalities, when observed, were generally mild, with hemorrhage and partial necrosis of the cranial kidney present in 27% of males. Mild damage or hematoma associated with the left kidney was also reported in 28% of females. The surgical objectives were achieved in 23 of 25 pigeons. The 2 surgical failures (regenerated testes in a male and large oviductal remnant in a female) were attributed to endosurgical inexperience and occurred during the first procedures. Salpingohysterectomy does not appear to prevent ovarian development and ovulation in the pigeon, at least not during the first 3 postoperative months. Orchidectomy and salpingohysterectomy appear to be safe procedures when performed using appropriate equipment and techniques. Endosurgery offers a valuable, minimally invasive alternative to the standard coeliotomy techniques commonly used in birds.

Evaluation of an endoscopic liver biopsy technique in green iguanas.

OBJECTIVE: To establish a safe and effective endoscopic technique for collection of liver biopsy specimens from lizards by use of a 2.7-mm rigid endoscope system that is commonly available in zoologic veterinary practice. DESIGN: Prospective study. ANIMALS: 11 subadult male green iguanas (Iguana iguana). PROCEDURES: Each lizard was anesthetized, and right-sided coelioscopic examination of the right liver lobe and gallbladder was performed. Three liver biopsy specimens were collected from each lizard by use of a 2.7-mm rigid endoscope and 1.7-mm (5-F) biopsy forceps. Biopsy samples were evaluated histologically for quality and crush artifact. Ten days following surgery, all iguanas were euthanatized and underwent full necropsy examination. RESULTS: For all 11 iguanas, the right liver lobe and gallbladder were successfully examined endoscopically, and 3 biopsy specimens of the liver were collected without complications. Mean +/- SD durations of anesthesia and surgery were 24 +/- 7 minutes and 6.8 +/- 1.0 minutes, respectively. At necropsy, there was no evidence of trauma or disease associated with the skin or muscle entry sites, liver, or any visceral structures in any iguana. All 33 biopsy specimens were considered acceptable for histologic interpretation; in most samples, the extent of crush artifact was considered minimal. CONCLUSIONS AND CLINICAL RELEVANCE: By use of a 2.7-mm rigid endoscope, liver biopsy procedures can be performed safely, swiftly, and easily in green iguanas. Biopsy specimens obtained by this technique are suitable for histologic examination. For evaluation of the liver and biopsy specimen collection in lizards, endoscopy is recommended.

Renal evaluation in the healthy green iguana (Iguana iguana): assessment of plasma biochemistry, glomerular filtration rate, and endoscopic biopsy.

Plasma biochemistry, iohexol clearance, endoscopic renal evaluation, and biopsy were performed in 23 clinically healthy 2-yr-old green iguanas (Iguana iguana). Mean (+/- SD) values for packed cell volume (30 +/- 3%), total protein (62 +/- 7 g/L, 6.2 +/- 0.7 g/dl), albumin (25 +/- 2 g/L, 2.5 +/- 0.2 g/dl), globulin (37 +/- 6 g/L, 3.7 +/- 0.6 g/ dl), total calcium (3.0 +/- 0.2 mmol/L, 12.0 +/- 0.7 mg/dl), ionized calcium (1.38 +/- 0.1 mmol/L), phosphorus (1.32 +/- 0.28 mmol/L, 4.1 +/- 0.9 mg/dl), uric acid (222 +/- 100 micromol/L, 3.8 +/- 1.7 mg/dl), sodium (148 +/- 3 mmol/L or mEq/ L), and potassium (2.6 +/- 0.4 mmol/L or mEq/L) were considered within normal limits. Values for urea were low (< 1.4 mmol/L, < 4 mg/dl) with 70% of samples below the detectable analyzer range. After the i.v. injection of 75 mg/ kg iohexol into the caudal (ventral coccygeal or tail) vein, serial blood collections were performed over 32 hr. Iohexol assays by high-performance liquid chromatography produced plasma iohexol clearance graphs for each lizard. A three-compartment model was used to fit area under the curve values and to obtain the glomerular filtration rate (GFR) using regression analysis. The mean GFR (SD) was 16.56 +/- 3.90 ml/kg/hr, with a 95% confidence interval of 14.78-18.34 ml/kg/hr. Bilateral endoscopic renal evaluation and biopsy provided tissue samples of excellent diagnostic quality, which correlated with tissue harvested at necropsy and evaluated histologically. None of the 23 animals demonstrated any adverse effects of iohexol clearance or endoscopy. Recommended diagnostics for the evaluation of renal function and disease in the green iguana include plasma biochemical profiles, iohexol clearance, endoscopic examination, and renal biopsy.

Diseases of the reptile pancreas.

A great deal of research is still needed to better understand the reptile pancreas especially with regard to diagnosis and treatment. However, vigilant clinicians and pathologists have important roles to play in expanding our knowledge base in this field, and are encouraged to share their findings through publications and presentations.

Veterinary management of snake reproduction.

The reptile veterinarian should approach the breeder with a comprehensive plan involving a review of proper husbandry, nutrition, record keeping, and a thorough prebreeding evaluation of the snakes. In addition, an evaluation of the reproductive strategy, assistance with confirming and monitoring gestation, and a review of potential reproductive complications will help to prepare the snake owner for a successful breeding season.