ArticleLiterature Review
To read the full-text of this research, you can request a copy directly from the authors.

Abstract

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 review discusses selected procedures and use of ultrasonography and diagnostic endoscopy.

No full-text available

Request Full-text Paper PDF

To read the full-text of this research,
you can request a copy directly from the authors.

... In probing, a lubricated, stainless-steel probe of the proper diameter is carefully and gently inserted into the side of the vent of the lizard (or even snake) and then directed towards the tail tip along the interior of the side of the tail. If the lizard is a male, the probe will slip inside the hemipenal pouch for approximately one quarter of the tail length, depending on the species [13]. If the probe advances only a short way to a depth of one to six scales [13,14], the lizard is considered a female, as there are no hemipenes for the probe to advance into [15]. ...
... If the lizard is a male, the probe will slip inside the hemipenal pouch for approximately one quarter of the tail length, depending on the species [13]. If the probe advances only a short way to a depth of one to six scales [13,14], the lizard is considered a female, as there are no hemipenes for the probe to advance into [15]. Probing is considered quite invasive and should be carefully performed to avoid tissue damage [12,14]. ...
... A variety of techniques have been used for sex determination in reptiles [1,[12][13][14]19,21]. Laparoscopy and laparotomy are well described techniques [22][23][24][25][26][27]. ...
Article
Full-text available
Sex determination has a fundamental role in a captive breeding context, both for commercial reasons and in relation to animal welfare itself. However, this can be particularly difficult, especially in reptiles with little or no sexual dimorphism. Twenty-three clinically healthy young Sierra Nevada lizards (Timon nevadensis) were included in this study for sex determination. The first attempt at sexing was carried out by cloacal probing. A small, buttoned probe was inserted very gently into the hemipenal pouches, and the length of the inserted part was evaluated and measured. Subsequently, for each animal, a contrast medium was administered into the cloaca, and radiography was performed within 5 min. Through probing, 11 males and 8 females were recognized. The test was, however, equivocal in four subjects. In contrast radiography, 14 males and 9 females were identified. All the animals were rechecked after 8 months through an ultrasound examination, confirming 15 of the 14 previously male sexed animals based on contrast radiography. All the animals identified as female (n = 9) by contrast radiography were confirmed. From these results, it seems that contrast radiography may have major sensitivity in sex determination compared to probing. This technique could represent a valid and less invasive aid for sexing young lizards.
... Treatment: Husbandry improvement of nesting box filled with sand placed in the enclosure. The monitor was given only supportive fluids of NaCl 0.9% with a dose of 20 mL/kg BW refer to Knotek et al. (2017) subcutaneously on both the hind legs. Owner was advised to do close observation back at home with placing a nest box into the monitor's enclosure. ...
... Fluid therapy was given subcutaneously divided on both hind legs with a dose of 20 mL/kg for maintaining the body fluids (Knotek et al. 2017). Clinically the V. salvator was still active and tongue was forking out normally. ...
... Noninvasive treatment and husbandry improvement was indicated in this case. Sexually maturity in captive animals could occur at early age due to the care and diet compared to age maturity for reproducing (Knotek et al. 2017). Young varanid which achieve earlier sexual maturity usually produce bigger egg but in lesser quantity (Thompson & Pianka 2001). ...
Article
Full-text available
Asian water monitor (Varanus salvator) is among the largest species of monitor lizards kept in captivity due to the elegancy and character of the species. Captive breeding projects of monitor lizards are not common among reptile keepers. A two years old female V. salvator was presented with complains of anorexic and distended abdomen. No record of copulation or egg deposition was noticed from the particular specimen. Radiography confirmed a post-ovulatory egg-stasis (POES) occurring in the coelomic cavity. Fluid therapy and husbandry improvement was indicated as treatments. Oviposition of the POES was noticed 4 days after treatment. Young monitors could be prone to have less quantity of eggs but larger in size.
... In animals of acceptable health status with normal sized and shaped eggs on radiography, medical therapy may be attempted. Calcium gluconate (100 mg/kg) is administered intramuscularly, with oxytocin (1-10 IU/kg) given by IM injection 1-2 hours later (Boyer, 1991;Knotek et al, 2017). However, retained eggs may develop adhesions and this approach can result in rupture of the thin-walled oviducts (Knotek et al, 2017). ...
... Calcium gluconate (100 mg/kg) is administered intramuscularly, with oxytocin (1-10 IU/kg) given by IM injection 1-2 hours later (Boyer, 1991;Knotek et al, 2017). However, retained eggs may develop adhesions and this approach can result in rupture of the thin-walled oviducts (Knotek et al, 2017). In debilitated animals, long-standing cases, or those with obstructive dystocia, surgical therapy is advisable after initial stabilisation. ...
... While not a disease, male iguanas may become aggressive and territorial when mature, and open surgical or endoscopic castration may be beneficial if carried out before sexual maturity (Knotek et al, 2017). The testicle is located in the caudal dorsal coelom and appears as a smooth ovoid soft tissue structure. ...
Article
Part one of this series discussed husbandry. This article (part 2) covers clinical procedures including sample collection, fluid therapy and anaesthesia and common presenting health concerns. These can be subdivided into non-infectious or husbandry associated conditions, and infectious disease. Nutritional secondary hyperparathyroidism, reproductive disease in females and renal disease are common reasons for seeking veterinary care. Presentation, diagnosis and treatment options are discussed for the common conditions.
... Female lizards (veiled chameleons, bearded dragons and green iguanas) kept under low quality husbandry practices (e.g. sub-optimal temperatures, limited exposure to UVB ultraviolet radiation, small terraria with crowding and stress and an insufficient feeding regime) suffer from retained ovarian follicles (or pre-ovulatory follicular stasis) and dystocia (or egg binding, post-ovulatory egg stasis) (Dorrestein et al. 2007;Kneidinger 2009;Knotek et al. 2009;Kummrow et al. 2010;Knotek et al. 2017). ...
... During the breeding season, female leopard geckos can lay between one and two eggs almost every two weeks, a physiologically demanding pro-cess often leading to severe reproductive and metabolic disorders (Dorrestein et al. 2007;Kneidinger 2009;Knotek et al. 2009;Kummrow et al. 2010;Knotek 2013;Knotek et al. 2017). Current methods of treatment of pre-ovulatory follicular stasis involve surgical treatment (ovariectomy, ovariohysterectomy) or conservative treatment (ovulation induction by the presence of a male leopard gecko) (Knotek et al. 2013). ...
Article
Full-text available
The aim of this study was to evaluate the effectiveness of deslorelin acetate in the regulation of reproductive activity in captive leopard geckos (Eublepharis macularius). Fourteen healthy adult females were separated into two groups. Under general anaesthesia, deslorelin acetate implants (4.7 mg) or placebo implants were administered into the coelom of ten female geckos and four female geckos, respectively. One healthy adult male Leopard gecko was added to each group of females (five females with GnRH implants and two females with placebo implants). The geckos were regularly monitored over two breeding seasons (visual examination, weight control). Nesting sites were checked daily. There were no postoperative complications or any other health problems during the study. Implant administration did not result in long-term suppression of reproductive function. No significant differences were found in the number of clutches between the female groups (deslorelin implants versus placebo implants) or in the number of clutches between the two breeding seasons. Deslorelin acetate implants did not interfere with ovarian activity in captive female leopard geckos. The use of GnRH agonist implants is not an appropriate method for control of reproductive function in female leopard geckos.
... carbonaria) com um quadro de prolapso peniano após trauma durante a cópula. O qual é considerado uma das principais causas de atendimentos e emergências na clínica de animais silvestres, sendo mais comum em répteis com histórico de trauma recente, afecções neurológicas, separação forçada durante a cópula, inflamação e hiperparatireoidismo secundário nutricional (RAMOS et al., 2009;KNOTEK et al., 2017). ...
... The most common reproductive issues in captive male squamates often involve the hemipenes 3,4 ; however, this case appears exceptional because of the size of the plug removed. The plug is not analogous to mammalian smegma because of the lack of sebaceous secretions in reptiles 5 ; it most likely comprises some combination of seminal fluid, desquamated keratinocytes, necrotic cell debris, holocrine scent gland secretions and/or foreign material from the environment; however, exact determination was outside the scope of this study. ...
Article
A rhinoceros viper presented with recurrent grey, thickened and crusted tissue protruding from the vent, with unilateral thickening and firmness of the left side of the base of the tail. Under anaesthesia, a plug of caseous material was removed from the inverted left hemipene. Fungal culture of the cloaca showed confluent growth of a single species, which could not be definitively identified at that stage. Because of the potential for Ophidiomyces ophidiicola, the causative agent of ophidiomycosis (snake fungal disease), antifungal treatments were initiated on Day 14. This included 30 minutes daily nebulisation with terbinafine dissolved in sterile saline and topical dilute betadine spray and enilconazole spray on the affected area, with infrequent oral terbinafine. Treatment continued until Day 101. The fungus was ultimately identified by a reference laboratory as a species of Fusarium sp. Clinical resolution was confirmed on Day 214. Aggressive treatment was chosen because of the risk that ophidiomycosis can present to a collection of snakes. K E Y WO R D S fungal dermatitis, fusarium, hemipenal plug, nebulisation, viper BACKGROUND
... The iguana was subsequently anesthetized and exploratory ventralceliotomy performed, in which eggs were found and a diagnosis of follicular stasis was made, which is a common reproductive problem in captive female lizards. 8 The eggs were removed and the iguana made a full recovery. At the time of surgery, no regrowth of the primary tumor, metastasis or abnormalities in relation to the tumor were seen. ...
Article
Full-text available
Reptiles are popular exotic pets and green iguanas (Iguana iguana) are amongst the top ten most popular reptiles. Here we describe a captive 8-year-old female green iguana that was referred for treatment of a non-healing, discharging lesion on the side of the body. The lesion was surgically excised and histopathological analysis revealed an epidermal proliferation of neoplastic keratinocytes, with focal infiltration through the basement membrane, into the underlying superficial dermis. Marked dysplastic changes, characterized by multifocal dyskeratosis and keratin pearl formation were also noted. A diagnosis of cutaneous squamous cell carcinoma (SCC) was made. Two years later, the iguana has shown no signs of recurrence. This is the first report of successful treatment of cutaneous SCC in a green iguana and contributes to the limited knowledge of cutaneous neoplasms in green iguanas.
... When clutches were found, we recorded the date of oviposition, number of eggs laid, and the number fertilized. Fertilization was confirmed by the presence of an area vasculosa (i.e., pink spot) on one side of the egg (Cuellar 1966b;Knotek et al. 2017). We kept eggs (n = 216) from each clutch (n = 21 S. undulatus, n = 16 S. woodi) together and we buried them completely in vermiculite that was premixed with water (water potential of -450 kPa) and placed inside a 120 ml glass jar. ...
Article
Full-text available
Oviductal sperm storage occurs in most squamate lineages, as well as in Tuatara. It is hypothesized to confer fitness benefits by increasing opportunities for reproductive success. These opportunities are specific to each selective landscape, but all are constrained by an underlying requisite phenotype, the duration that sperm can be stored and remain viable. Functional sperm storage durations are generally estimated by field observations of reproductive ecology or the presence of sperm in the oviduct, with few direct tests of sperm viability over time or reproductive events. In sceloporine lizards of the family Phrynosomatidae, functional sperm storage has been examined in many viviparous species with asynchronous reproduction, but oviparous species with synchronous reproduction have not been examined. We assessed functional sperm storage in two oviparous sceloporine lizards with synchronous reproduction, the Eastern Fence Lizard (Sceloporus undulatus) and the Florida Scrub Lizard (S. woodi). Over a 4-mo period of isolation, we found reproductive success of gravid females declined in both species (3.9% per week in S. undulatus and 6.7% in S. woodi), although moderate levels of fertility and hatching success were observed for up to 12 weeks in S. undulatus and 14 weeks in S. woodi. Our data suggest, for these populations, that functional sperm storage occurs across the reproductive season, but is unlikely to continue into the next year.
... In avian species, DA implants are rarely employed, usually to medically reduce aggressivity or treat sex-related disorders such as excessive egg laying, with great variability in efficacy and duration [18][19][20][21][22][23]. In reptiles, GnRH agonists have been poorly investigated so far: in lizards, suppression of gonadic activity was reported only in iguanas [18,[24][25][26]. Regarding chelonians, annual applications of DA implants reduced serum testosterone levels after the fourth treatment in a male Chelonia mydas [27]; DA was successfully used to treat chronic ovodeposition problems in a Testudo graeca up to 24 months after implantation [28]. ...
Article
Full-text available
The use of long-acting gonadotropin-releasing hormone (GnRH) agonists to suppress fertility has been poorly investigated in reptiles, and the few available studies show inconsistent results. The efficacy of single and double intramuscular 4.7 mg deslorelin acetate implants in captive pond sliders (Trachemys scripta) was investigated, with 20 animals divided into three groups: a single-implant group (6 animals), a double-implant group (6 animals), and a control group (no implant). During one reproductive season (March to October), plasmatic concentration of sexual hormones (estradiol, progesterone, and testosterone) and ovarian morphometric activity via computed tomography were monitored about every 30 days. A significative decrease in the number of phase II ovarian follicles was detected in the double-implant group compared with the control group, but no significant difference was noted in the number of phase III and phase IV follicles, egg production, and plasmatic concentration of sexual hormones. Results show that neither a single nor a double deslorelin acetate implant can successfully inhibit reproduction in female pond sliders during the ongoing season, but the lower number of phase II follicles in the double-implant group can possibly be associated with reduced fertility in the following seasons.
... The right testicle is located cranially to the left one. Male lizards have two hemipenes and crocodiles have a single penis (16,25). ...
Article
Full-text available
Reptiles are increasingly being used as pets worldwide.The most encountered species are turtles,snakes or lizards, and their popularity leads to the need for specialization of clinicians and pathologists alike in order to solve the exotic animal cases. Necropsy examination is a vital tool in establishing the post-mortem diagnosis. In order to obtain a higher quantity and quality of information following a necropsy examination, it is necessary to know the technique, as well as to implement a well-developed protocol. Reptiles, wild or pets, are exotic species that, by their anatomical particularities, require a different necropsy protocol than mammals. This paper aims to present various techniques for necropsy and gross examination of organs in reptiles.
Article
Reptile surgery, as well as owner expectations for the care of reptiles, is constantly evolving. It is essential that the unique anatomical and physiological differences between reptiles and mammal patients, as well as between reptiles of different groups, be fully understood before undertaking any surgery. All reptile patients should undergo a full clinical examination and be stabilised wherever possible before surgery, with the patient's preferred optimum temperature being ensured pre-, peri- and postoperatively to optimise drug metabolism and wound healing. It is important to optimise patient and surgeon positioning, use appropriately sized suture material, and maintain haemostasis, magnification and lighting to improve surgical technique, regardless of the procedure or organ system being operated on.
Article
Background Veiled chameleons (Chamaeleo calyptratus) are more frequently presented to veterinary clinics due to reproductive diseases that lead to high morbidity, especially in captive-bred females. The objective of this study was to evaluate blood biochemical profiles of healthy, young captive females veiled chameleon in the age of seven, nine and eleven months. Methods Blood samples were taken from 20 female veiled chameleons at the age of 7, 9 and 11 months. The biochemical profile was analyzed using the VetScan VS2 analyzer with an Avian/Reptile Profile rotor. The ionized calcium (iCa) concentration was measured by i-STAT analyzer with a CHEM+8 cartridge. Result Mean concentration of glucose (15.8 ± 1.3 mmol/l) and uric acid (244.3 ± 143.2 µmol/l) at the age of seven month were significantly higher than mean concentrations of glucose (12.8 ± 16.5 mmol/l) and uric acid (134.9 ± 113.2 µmol/l) at the ninth month and mean concentration of glucose (13.2 ± 0.9 mmol/l) and uric acid (129.4 ± 109.2 µmol/l) at the eleventh month, respectively. Total calcium (4.2 ± 0.8 mmol/l) and ionized calcium (1.51 ± 0.16 mmol/l) were significantly higher at the seventh month compare to ninth month. Mean activity of aspartate aminotransferase at the ninth month (6.2 ± 2.3 µkat/l) was significantly higher (P=0.004) than the mean activity of aspartate aminotransferase at the seventh month (4.7 ± 1.0 µkat/l). Concentrations of potassium at the eleventh month (8.3 ± 2.1 mmol/l) were significantly higher (P˂0.001) than the mean concentration of potassium at the seventh month (5.4 ± 1.3 mmol/l) and also at the ninth month (6.1 ± 1.6 mmol/l). No significant differences were found among the mean concentrations of total protein (57.5 ± 14.6, 61.9 ± 9.2, 59.6 ± 12.2 g/l), albumin (32.8 ± 5.4, 33.6 ± 4.1, 33.4 ± 7.1 g/l), globulin (27.4 ± 5.4, 26.6 ± 4.3, 26.3 ± 5.4 g/l) and mean activity of creatine kinase (25.4 ± 10.3, 30.1 ± 21.0, 25.6 ±13.2 µkat/l). Conclusions and clinical relevance In all females, ovarian activity was already evident in the first part of monitoring, and the measured values could be interpreted as values for young female veiled chameleons during active ovarian activity.
Article
Geckos are a large infraorder of small lizards that comprise over 1300 species. The leopard gecko (Eublepharis macularius) is by far the most popular species of captive gecko. This chapter discusses the husbandry, clinical conditions, basic intervention techniques, common infectious and non‐infectious conditions of various species of geckos, including Tokay geckos, Day geckos, mourning geckos, African fat‐tail geckos, and crested geckos. The basic intervention techniques include nutritional support, anaesthesia, fluid therapy, and euthanasia. The non‐infectious conditions cover anorexia, nutritional secondary hyperparathyroidism, ophthalmic disease, neurological disease, and reproductive disorders. The infectious conditions include endoparasites, dermatitis, and viral infections. Preventative health measures are limited in geckos. In most cases focus is mainly on intestinal parasite screening and maintaining good standards of husbandry to reduce incidence of many of the common diseases.
Article
The green iguana (Iguana iguana) is a large arboreal lizard with complex environmental requirements, generally making this a poor choice as a companion animal. Husbandry deficiencies are a common contributor to clinical disease, and it is important to be aware of the environmental conditions for this species and relevance of any deficiencies to animal health. This article covers the husbandry of this species. Part 2 will focus on sample collection and common presenting health concerns.
Article
Full-text available
The aim of this study was to evaluate short-term intravenous anaesthesia with alfaxalone in green iguanas (Iguana iguana). Alfaxalone at a dose rate of 5 mg/kg was administered to thirteen adult male green iguanas via the ventral caudal vein following 24 h fasting. The induction time, tracheal tube insertion time, surgical plane of anaesthesia interval, and full recovery time were recorded. Systolic, diastolic and mean arterial blood pressure (measured indirectly), pulse rate, respiratory rate, SpO(2) and ETCO2 were recorded. The induction time and tracheal tube insertion time was 41.54 +/- 27.69 s and 69.62 +/- 37.03 s, respectively. The time from the alfaxalone administration to the loss of toe-pinch reflex was 2.20 +/- 1.47 mm. Full activity was restored 14.23 +/- 4.15 min after the initial alfaxalone administration. The respiratory rate increased significantly (P < 0.01) from 4.3. +/- 3.2 to 6.8 +/- 1.6 breaths per mm and a gradual decrease of ETCO2 from 43.65 +/- 10.54 to 26.58 +/- 8.10 mmHg (P < 0.01) was noted from the second to the 13th mm after alfaxalone administration. The pulse rate, SpO(2) and blood pressure did not change significantly. Intravenous use of alfaxalone proved to be a suitable and safe form for short term anaesthesia in green iguanas.
Book
This outstanding clinical reference provides valuable insights into solving clinical dilemmas, formulating diagnoses, developing therapeutic plans, and verifying drug dosages for both reptiles and amphibians. The information is outlined in an easy-to-use format for quick access that is essential for emergency and clinical situations. Discusses veterinary medicine and surgery for both reptiles and amphibians Features complete biology of snakes, lizards, turtles, and crocodilians Provides step-by-step guidelines for performing special techniques and procedures such as anesthesia, clinical pathology, diagnostic imaging, euthanasia and necropsy, fracture management, soft tissue surgery, and therapeutics Covers specific diseases and conditions such as anorexia, aural abscesses, and digit abnormalities in a separate alphabetically organized section 53 expert authors contribute crucial information to the study of reptiles and offer their unique perspectives on particular areas of study The expansive appendix includes a reptile and amphibian formulary A new full-color format features a wealth of vivid images and features that highlight important concepts and bring key procedures to life 29 new chapters covering diverse topics such as stress in captive reptiles, emergency and critical care, ultrasound, endoscopy, and working with venomous species Many new expert contributors that share valuable knowledge and insights from their experiences in practicing reptile medicine and surgery Unique coverage of cutting-edge imaging techniques, including CT and MRI.
Article
The surgical approach to reptiles can be challenging. Reptiles have unique physiologic, anatomic, and pathologic differences. This may result in frustrating surgical experiences. However, recent investigations provided novel, less invasive, surgical techniques. The purpose of this review was to describe the technical aspects behind soft tissue surgical techniques that have been used in reptiles, so as to provide a general guideline for veterinarians working with reptiles.
Book
Contents Specialization in Reptile Medicine SECTION I: ADVANCES IN REPTILE MEDICINE 1. Current Herpetological Husbandry and Products 2. Common Pathology and Diseases Seen in Pet Store Reptiles 3. Clinical Aspects of Evolution in Reptile Medicine 4. Molecular Infectious Disease Diagnostics 5. Clinical Virology 6. Updates on Fungal Infections in Reptiles 7. Therapeutics 8. Clinical Pathology 9. CT and MRI 10. Ultrasonography 11. Conditioning and Behavioral Training in Reptiles SECTION II: ADVANCES IN ANESTHESIA, SURGERY AND ANALGESIA 12. Anesthesia 13. Diagnostic Endoscopy 14. Endosurgery 15. Vacuum Assisted Wound Closure in Chelonians 16. New Techniques in Chelonian Shell Repair 17. Video Telescopic Operating Microscope: A Recent Development in Reptile Microsurgery 18. Analgesia 19. Reptiles and Amphibians in Laboratory Animal Medicine SECTION III: ADVANCES IN AMPHIBIAN MEDICINE 20. Amphibian Therapy 21. Amphibian Diversity in a New Era of Amphibian Taxonomy 22. Exhibiting Amphibians 23. Infectious Diseases of Amphibians: It Isn't Just Redleg Anymore 24. Chytridiomycosis 25. Short Tongue Syndrome and Hypovitaminosis A 26. Ranaviruses SECTION IV: ADVANCES IN BIOLOGY, CONSERVATION, LEGAL AND RESEARCH 27. Conservation Issues 28. Invasive and Introduced Reptiles and Amphibians 29. Techniques for Working with Wild Reptiles 30. Forensics in Reptile Investigation APPENDICES Appendix 1: Developing your Reptile Medicine IQ: Learning How to Get the Most Out of and Contribute to the Herpetologic Literature Appendix 2: Drug Formulary and Laboratory Normals
Article
Endoscopy has proven to be a most useful diagnostic tool in veterinary medicine. In the field of zoological medicine, the application of diagnostic endoscopy has shown great promise in a variety of species, but has probably been most exploited by avian veterinarians. To date, endoscopy in reptiles has not enjoyed widespread acceptance, although there are numerous reports to indicate its use since the 1960s. The aim of this article is to introduce the clinician to lizard, and more specifically, iguana endoscopy, using new developments in equipment. Preferred instrumentation, patient preparation, and endoscopic techniques, including tissue biopsy, will be described.
Article
Reproductive failure, in particular preovulatory stasis, is a common problem in captive female reptiles. For a better understanding of its pathogenesis, the patterns of fecal estradiol (E2), testosterone (T), progesterone (P) and their metabolites of 21 anovulatory female veiled chameleons, Chamaeleo calyptratus, were compared with those of 25 animals which ovulated during at least one cycle over the study period. Regular, cyclical hormone patterns, consisting of E2 peaks followed by simultaneous T and P peaks, were observed in all animals, regardless of whether oviposition occurred, indicating continuous ovarian activity. P concentrations were; however, significantly lower in animals undergoing anovulatory cycles. The average time period between the E2 and the T peak was 24.8 days, between the E2 and the P peak 26.5 days, and between the T and P peak 2.6 days. The mean length of reproductive cycles between two sequential ovulatory complexes (oviposition to oviposition) was 132.5 days (range 112-156 days). The results provide evidence that reproductive "failure" occurs more frequently than suspected with some females alternating between ovulatory and anovulatory cycles without any outward evidence of the variation in ovarian cycles. It is proposed that this may be related to physiological adaptation to adverse environmental conditions for breeding and that husbandry factors in captivity are primarily responsible for the progression from a physiological to pathological process.
Article
Reptiles have gained popularity in the North American and European pet trade. Large numbers of captive-born veiled chameleons, Chamaeleo calyptratus, are produced annually but knowledge of their reproductive cycle has been limited to anecdotal observations. This study describes the hormonal changes associated with reproductive cycling in female veiled chameleons using non-invasive fecal evaluation of metabolites of the three principal ovarian steroids, estradiol (E2), testosterone (T), progesterone (P), and their metabolites, by enzyme immunoassays. The hormone patterns were compared with follicular development and ovulation as determined by magnetic resonance imaging (MRI). Three main cycle stages were identified on MRI: the previtellogenic stage (PV) with the absence of visible follicular structures, vitellogenic stage (V) with the presence of round follicular structures >2mm diameter, and the gravid stage with the presence of oval egg structures. Although the absolute values of the baselines and peaks for each hormone varied among animals, approximately 24-fold increases over mean P baseline values and 7.5-fold increases over mean E2 and T baseline values were associated with biological events. E2 rose during vitellogenesis, peaked in late vitellogenesis and fell shortly thereafter. P rose during the late vitellogenic stage, peaked in mid-gravidity and fell to baseline values at oviposition. Ovulation occurred with the decreasing E2:P ratio. T levels varied during the pre- and vitellogenic stages then mirrored P with a distinct peak during the time of ovulation and gravidity. These data provides us with the necessary background for future studies on the reproductive biology of this species.
Article
The 2.7-mm telescope commonly used in avian practice has transitioned into an invaluable diagnostic tool for the reptile clinician. Previously plagued by vague medical histories, nonpathognomonic physical examinations, indistinct diagnostic images, and less than conclusive clinical pathology results, the reptile clinician often has had trouble making a definitive, antemortem diagnosis. A definitive diagnosis generally relies on the demonstration of a host pathologic response and the causative agent. The ability to examine internal structures and collect biopsies has enabled many postmortem diagnoses to now be appreciated in the living animal, and along with accurate diagnosis comes accurate prognosis and improved case management. The advent of 3-mm human pediatric laparoscopy equipment has fueled interest in minimally invasive endosurgery in exotic pets, including reptiles. However, the chelonian shell has also served as a catalyst to speed the development of surgical approaches to the coelom that do not involve major shell surgery. This article summarizes the most common endoscopic approaches in lizards, chelonians, and snakes for the purposes of making a diagnosis and increasingly performing endosurgery.
Article
Female green iguanas, Iguana iguana, were caught in Belize, Central America (17 degrees N), in December, at the onset of seasonal gonadal activity. The animals were immediately transferred to San Diego (32 degrees N). Ovarian follicular development continued, with peak plasma hormone levels measured in January and February; 200 pg/ml for progesterone (P) and 800 pg/ml for total estrogens (Et = estradiol [E2] + estrone [E1]). E2 was the predominant estrogen throughout the cycle. Follicular atrophy was indicated in April with circulating progesterone and estrogen levels decreasing to baseline (refractory phase) levels (P = 20 pg/ml; Et = 50 pg/ml). Approximately midway through the refractory phase of their annual reproductive cycle (late May), either the D-Arg6 analog of Chicken II or mammalian GnRH was administered via intraperitoneal osmotic pumps for 14 days to nine females. The analog of chicken II induced a fivefold increase in total circulating estrogens within 3-4 days after implantation. Both continuous and pulsatile delivery of the chicken II analog produced a similar pattern of steroidogenic response. A radical sham control animal showed no increase in steroidogenesis. Mammalian GnRH produced a pattern of similar duration, although the magnitude of the steroidogenic response was only half that produced by the chicken II analog. Estrogen titers approached baseline levels in all treatment groups two days after treatment ceased. Progesterone levels increased in all treatment groups during the delivery of exogenous GnRH, although the increases were not consistent. Untreated male cagemates housed with treated females exhibited increased territoriality, courtship behavior, and mating, which began on day 4 or 5 of the treatment period. The control female was not courted by its male cagemate.
Lizards are a diverse group of some 4470 species, a wide variety of which are now kept in captivity. Interest in captive lizards continues to increase, wild populations seem to be declining in some areas, and herpetoculturists continue to succeed in breeding more species; consequently, veterinarians must understand basic lizard reproductive biology to successfully treat lizard patients with reproductive problems. Just obtaining First Filial Generation (F1) offspring is an accomplishment. But we must look down the road to maintain a species in captivity for succeeding generations, and a lineage may not continue if attention is not given to details of appropriate husbandry and proper reproductive pursuits. One study documents the senescence of lineages in parthenogenetic lizards in captivity apparently associated with husbandry problems [99].
Evaluating the effect of leuprolide acetate on testosterone levels in captive male green iguanas
  • M Kirchgesser
  • M Mitchell
  • L Domenzain
Kirchgesser M, Mitchell M, Domenzain L, et al. Evaluating the effect of leuprolide acetate on testosterone levels in captive male green iguanas (Iguana iguana).
The urogenital system of reptiles
  • A Fox
Fox A. The urogenital system of reptiles. In: Gans C, Parsons TS, editors. Biology of the Reptilia, vol. 6. London: Academic Press; 1977. p. 1-157.
GnRH implant in green iguana
  • N Kneidinger
Kneidinger N. GnRH implant in green iguana (Iguana iguana) [Thesis].
BSAVA manual of reptiles
  • Jd Johnson
  • Urogenital
Johnson JD. Urogenital system. In: Girling SJ, Raiti P, editors. BSAVA manual of reptiles. 2nd edition. Quedgeley (United Kingdom): BSAVA; 2004. p. 261-72.
Removal of a testicular tumor from a veiled chameleon (Chamaeleo calyptratus)
  • K Biron
  • K Heckers
Biron K, Heckers K. Removal of a testicular tumor from a veiled chameleon (Chamaeleo calyptratus). Proceedings of the Annual Conference Association Reptilian and Amphibian Veterinarians. South Padre Island (TX), 2010. p. 77-8.
Reproductive strategies in captive female veiled chameleons
  • Z Knotek
Knotek Z. Reproductive strategies in captive female veiled chameleons. Proceedings of the UPAV/AAVAC/ARAV Conference. Cairns, April 22-24, 2014. p. 127-30.
Haematology and plasma chemistry in female veiled chameleons (Chamaeleo calyptratus) suffering from preovulatory follicle stasis (POFS)
  • Z Knotek
  • G M Dorrestein
  • Z Knotkova
Knotek Z, Dorrestein GM, Knotkova Z, et al. Haematology and plasma chemistry in female veiled chameleons (Chamaeleo calyptratus) suffering from preovulatory follicle stasis (POFS). Proceedings of the Annual Conference European Association of Zoo and Wildlife Veterinarians. Leipzig, April 30-May 3, 2008. p. 189-95.
Diagnostic and surgical endoscopy
  • Hernandez-Divers
  • Sj
Hernandez-Divers SJ. Diagnostic and surgical endoscopy. In: Girling SJ, Raiti P, editors. BSAVA manual of reptiles. 2nd edition. Quedgeley (United Kingdom): BSAVA; 2004. p. 103-14.
Alfaxalone anaesthesia in veiled chameleon (Chamaeleo calyptratus)
  • Z Knotek
  • A Hrda
  • N Kley
Knotek Z, Hrda A, Kley N, et al. Alfaxalone anaesthesia in veiled chameleon (Chamaeleo calyptratus). Proceedings of the Annual Conference Association Reptilian and Amphibian Veterinarians. Seattle, August 6-12, 2011. p. 179-81.
United Kingdom): BSAVA; 1992
  • P Zwart
Zwart P. Urogenital system. In: Beynon PH, Lawton MPC, Cooper J, editors. BSAVA manual of reptiles. 1st edition. Cheltenham (United Kingdom): BSAVA; 1992. p. 117-27.
Endoscopic examination of the urogenital tract in reptiles
  • B Schildger
Schildger B. Endoscopic examination of the urogenital tract in reptiles. Proceedings of the Annual Conference Association Reptilian and Amphibian Veterinarians. Pittsburgh, October 22-24, 1994. p. 60-1.
Haemogram and plasma chemistry in female green iguana with POOS versus POFS syndrome
  • Z Knotkova
  • S Pelrilova
  • Z Knotek
Knotkova Z, Pelrilova S, Knotek Z. Haemogram and plasma chemistry in female green iguana with POOS versus POFS syndrome. Proceedings of the Annual Conference European Association of Zoo and Wildlife Veterinarians. Ebeltoft, May 19-23, 2004. p. 287-9.
Surgical removal of cyst in the testis of Yemen chameleon (in Czech)
  • Z Knotek
  • Barazorda Romero
  • S Knotkova
Knotek Z, Barazorda Romero S, Knotkova Z, et al. Surgical removal of cyst in the testis of Yemen chameleon (in Czech). Veterinarni klinika 2013;10:153-7.
Reproductive endocrinology in reptiles
  • Z Knotek
  • Z Knotkova
  • E Mö Stl
Knotek Z, Knotkova Z, Mö stl E, et al. Reproductive endocrinology in reptiles. Proceedings of the Conference Amphibian and Reptilian Veterinarians. Cremona, May 13-15, 2012, p. 44-7.
Reptile medicine and surgery
  • S L Barten
  • Penile Prolapse
Barten SL. Penile prolapse. In: Mader DR, editor. Reptile medicine and surgery. 2nd edition. St Louis (MO): Elsevier Saunders; 2006. p. 862-4.
Quedgeley (United Kingdom): British Small Animal Veterinary Association
  • Hernandez-Divers
  • Sj
Hernandez-Divers SJ. Surgery: principles and techniques. In: Girling SJ, Raiti P, editors. BSAVA manual of reptiles. 2nd edition. Quedgeley (United Kingdom): British Small Animal Veterinary Association; 2004. p. 147-67.
Surgery in chameleons
  • Z Knotek
Knotek Z. Surgery in chameleons. Proceedings of the UPAV/AAVAC/ARAV Conference. Cairns, April 22-24, 2014. p. 212-21.
Current therapy in reptile medicine and surgery
  • C Hochleithner
  • M Holland
  • Ultrasonography
Hochleithner C, Holland M. Ultrasonography. In: Mader DR, Divers SJ, editors. Current therapy in reptile medicine and surgery. St Louis (MO): Elsevier Saunders; 2014. p. 107-27.