RESUMEN
Ex situ breeding constitutes an important tool for species conservation; however, many reptile species are not managed sustainably under human care due to poor fecundity in ex situ settings. In this study, we tested whether the translocation of a seasonally reproducing species to a different environment results in decoupling of extrinsic signals and intrinsic conditions. The endocrinological patterns of plasma steroid sex hormones, follicular development, and mating behaviour of two female and two male sexually mature Aldabra tortoises (Aldabrachelys gigantea) in a zoological institution in the Northern hemisphere was aligned with enclosure climate data (mean monthly daylight duration, temperature, and precipitation) and compared with respective hormone patterns of wild individuals and climate conditions in the native habitat on the Aldabra Atoll in the Southern hemisphere. Whereas occurrence of mating behaviour was not considered a limiting factor, lack of ovulation and subsequent follicular atresia was the main reason for the lack of reproductive output. While it was impossible to elucidate the triggering factors of ovulation and the multifactorial complexity of reproduction was not fully addressed, this study indicates suboptimal temperature conditions and relative temporal shifts of interacting external triggers (temperature and photoperiod) in the zoo setting.
RESUMEN
Female veiled chameleons, Chamaeleo calyptratus, have a high fecundity and fast maturation, which makes them a suitable model species for squamate reproduction. The authors investigated the morphological follicular development of a group of 20 healthy adult animals over a 12-mon period using ultrasonography (US) and CT. Four stages of follicular development could be distinguished by imaging diagnostics and were confirmed by histology: previtellogenesis, vitellogenesis, gravidity, and atresia. Using a linear ultrasound transducer (18 MHz), previtellogenic follicles could be visualized as small, round, hypoechoic structures. Identification of this stage was unreliable on CT. On US, vitellogenic follicles remained round and showed increasing echogenicity from the hypoechoic center outwards, displaying vinyl-like hyperechoic banding in later stages. On CT, early vitellogenic follicles were round, hyperdense structures, which reduced in density as they grew. A hyperdense inner ring with a hypodense central point characterized late vitellogenesis. Following ovulation, eggs became distinctly oval on both CT and US, with formation of a hyperdense or hyperechoic outer ring, respectively. Atresia followed in cases where no ovulation occurred, and was divided into yolky and cystic atresia. Sonographically, early yolky atretic follicles became unevenly shaped, packed against one another, and developed heterogenous content. Late atretic follicles were homogenous and reduced in size. Reduction of density and uneven shape were also observed on CT. Cystic atretic follicles developed an anechoic cavity with a dense peripheral accumulation of content. In many animals 2-3 generations of atretic follicles were observed without indication of impairment to the development of the newest batch of follicles. Thus, follicular atresia need not necessarily lead to a pathological condition in veiled chameleons, at least not within a few consecutive cycles.
Asunto(s)
Atresia Folicular , Lagartos , Femenino , Animales , Reproducción , Ovulación , Tomografía Computarizada por Rayos XRESUMEN
The relationship between the reproductive (hypothalamic-pituitary-gonadal; HPG) and adrenal (hypothalamic-pituitary-adrenal; HPA) hormone axes is complex and can vary depending on the species and environmental factors affecting an individual. In an effort to understand this relationship in female veiled chameleons (Chamaeleo calyptratus), the patterns of fecal metabolites of corticosterone (C), estradiol (E), testosterone (T), and progesterone (P) were analyzed by enzyme immunoassay (EIA) during ovulatory (OC; eggs laid) and non-ovulatory cycles (NOC; no eggs laid). Glucocorticoid (GC) metabolites in the fecal extracts were characterized by HPLC and corticosterone EIA performance was assessed by parallelism, accuracy and precision tests. The results indicated that the assay chosen reliably measured the hormone metabolites present in the fecal extracts. Regular, cyclical hormone metabolite patterns consisting of an E peak followed by peaks of T, P and C in close succession were observed during both ovulatory and non-ovulatory cycles; relative levels of P and C, however, were higher during ovulatory cycles. Corticosterone metabolite levels, in particular, increased throughout vitellogenesis and peaked in late vitellogenesis (in non-ovulatory cycles) or around the time of ovulation, and remained elevated throughout the gravid period, falling just prior to oviposition. The results provide evidence of variation in glucocorticoid production throughout different stages of the reproductive cycle, including a role in the ovulatory process; the physiology, however, remains unclear.
Asunto(s)
Lagartos , Ovulación , Progesterona , Animales , Estradiol/metabolismo , Femenino , Lagartos/metabolismo , Progesterona/metabolismo , Reproducción/fisiología , Testosterona/metabolismoRESUMEN
Despite the growing knowledge and literature on primate medicine, assessment and treatment of behavioral abnormalities in nonhuman primates (NHPs) is an underdeveloped field. There is ample evidence for similarity between humans and great apes, including basic neurologic physiology and emotional processes, and no substantial argument exists against a concept of continuity for abnormal conditions in NHPs that emerge in response to adverse experiences, akin to human psychopathology. NHPs have served as models for human psychopathologies for many decades, but the acquired knowledge has only hesitantly been applied to primates themselves. This review aims to raise awareness among the veterinary community of the wealth of literature on NHP psychopathologies in human medicine and anthropology literature and calls for the necessity to include mental health assessments and professionally structured treatment approaches in NHP medicine. Growing understanding about causes and pathogenesis of abnormal behavior in NHP will not only help to prevent the development of undesirable behaviors but also allow for treatment and management of long-lived, already affected animal patients.
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Enfermedades del Simio Antropoideo/diagnóstico , Enfermedades del Simio Antropoideo/prevención & control , Trastornos Mentales/veterinaria , Enfermedades de los Monos/diagnóstico , Enfermedades de los Monos/prevención & control , Primates , Animales , Enfermedades del Simio Antropoideo/psicología , Trastornos Mentales/diagnóstico , Trastornos Mentales/psicología , Trastornos Mentales/terapia , Enfermedades de los Monos/psicología , Primates/psicología , PsicopatologíaRESUMEN
In 2015, we identified an avian hepatitis B virus associated with hepatitis in a group of captive elegant-crested tinamous (Eudromia elegans) in Germany. The full-length genome of this virus shares <76% sequence identity with other avihepadnaviruses. The virus may therefore be considered a new extant avian hepadnavirus.
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Enfermedades de las Aves/epidemiología , Genoma Viral , Infecciones por Hepadnaviridae/veterinaria , Hepadnaviridae/genética , Hepatitis Viral Animal/epidemiología , Proteínas Virales/genética , Animales , Animales de Zoológico , Evolución Biológica , Enfermedades de las Aves/patología , Enfermedades de las Aves/virología , Extinción Biológica , Alemania/epidemiología , Hepadnaviridae/clasificación , Hepadnaviridae/aislamiento & purificación , Infecciones por Hepadnaviridae/epidemiología , Infecciones por Hepadnaviridae/patología , Infecciones por Hepadnaviridae/virología , Hepatitis Viral Animal/patología , Hepatitis Viral Animal/virología , Especificidad del Huésped , Humanos , Hígado/patología , Hígado/virología , Sistemas de Lectura Abierta , Paleognatos/virología , FilogeniaRESUMEN
OBJECTIVE: To characterize a propofol-medetomidine-ketamine total intravenous anaesthetic in impala (Aepyceros melampus). STUDY DESIGN: Prospective clinical study. ANIMALS: Ten adult female impala. MATERIALS AND METHODS: Impala were immobilized at 1253 m above sea level with 2.0 mg thiafentanil and 2.2 mg medetomidine via projectile darts. Propofol was given to effect (0.5 mg kg-1 boluses) to allow endotracheal intubation, following which oxygen was supplemented at 2 L minute-1. Anaesthesia was maintained with a constant-rate infusion of medetomidine and ketamine at 5 µg kg-1 hour-1 and 1.5 mg kg-1 hour-1, respectively, and propofol to effect (initially 0.2 mg kg-1 minute-1) for 120 minutes. The propofol infusion was titrated according to reaction to nociceptive stimuli every 15 minutes. Cardiopulmonary parameters were monitored continuously and arterial blood gas samples were analysed intermittently. After 120 minutes' maintenance, the thiafentanil and medetomidine were antagonized using naltrexone (10:1 thiafentanil) and atipamezole (5:1 medetomidine), respectively. RESULTS: All impala were successfully immobilized. The median dose [interquartile range (IQR)] of propofol required for intubation was 2.7 (1.9-3.3) mg kg-1. The propofol-medetomidine-ketamine combination abolished voluntary movement and ensured anaesthesia for the 120 minute period. Propofol titration showed a generally downward trend. Median (IQR) heart rate [57 (53-61) beats minute-1], respiratory rate [10 (9-12) breaths minute-1] and mean arterial blood pressure [101 (98-106) mmHg] were well maintained. Arterial blood gas analysis indicated hypoxaemia, hyper- capnia and acidaemia. Butorphanol (0.12 mg kg-1) was an essential rescue drug to counteract thiafentanil-induced respiratory depression. All impala regurgitated frequently during the maintenance period. Recovery was calm and rapid in all animals. Median (IQR) time to standing from antagonist administration was 4.4 (3.2-5.6) minutes. CONCLUSIONS AND CLINICAL RELEVANCE: A propofol-medetomidine-ketamine combination could provide adequate anaesthesia for invasive procedures in impala. The propofol infusion should begin at 0.2 mg kg-1 minute-1 and be titrated to clinical effect. Oxygen supplementation and airway protection with a cuffed endotracheal tube are essential.
Asunto(s)
Anestesia Intravenosa/veterinaria , Anestésicos Combinados/administración & dosificación , Antílopes , Fentanilo/análogos & derivados , Hipnóticos y Sedantes/administración & dosificación , Ketamina/administración & dosificación , Medetomidina/administración & dosificación , Propofol/administración & dosificación , Antagonistas de Receptores Adrenérgicos alfa 2/administración & dosificación , Anestesia Intravenosa/métodos , Animales , Femenino , Fentanilo/administración & dosificación , Fentanilo/antagonistas & inhibidores , Frecuencia Cardíaca/efectos de los fármacos , Hipnóticos y Sedantes/antagonistas & inhibidores , Imidazoles/administración & dosificación , Medetomidina/antagonistas & inhibidores , Naltrexona/administración & dosificación , Antagonistas de Narcóticos/administración & dosificación , Estudios Prospectivos , Frecuencia Respiratoria/efectos de los fármacosRESUMEN
In order to develop a long-term anesthesia for flighty antelope species in field situations, two different protocols for induction and maintenance with an intravenous infusion were evaluated in wild-caught impala ( Aepyceros melampus ). Ten adult female impala were induced with two induction protocols: one consisted of 0.2 mg/kg medetomidine, 4 mg/kg ketamine, and 0.15 mg/kg butorphanol (MKB) and one consisted of 0.375 mg/kg etorphine, 0.2 mg/kg medetomidine, and 0.2 mg/kg midazolam (EMM). In both treatments, anesthesia was maintained with a continuous intravenous infusion (CII) at an initial dose rate of 1.2 µg/kg per hr medetomidine, 2.4 mg/kg per hr ketaminen and 36 µg/kg per hr midazolam. Partial reversal was achieved with naltrexone (2 : 1 mg butorphanol; 20 : 1 mg etorphine) and atipamezole (5 : 1 mg medetomidine). Evaluation of anesthesia included respiratory rate, heart rate, rectal temperature, arterial blood pressure, oxygen saturation, end tidal carbon dioxide tension, and tidal volume at 5-min intervals, palpebral reflex and response to painful stimuli at 15-min intervals, and arterial blood gases at 30-min intervals. Plasma cortisol concentration was determined after induction and before reversal. Duration and quality of induction and recovery were evaluated. EMM caused a faster induction of 9.5 ± 2.9 min compared to 11.0 ± 6.4 min in MKB. Recovery was also quicker in EMM (EMM: 6.3 ± 5.4 min; MKB: 9.8 ± 6.0 min). However, EMM also produced more cardiopulmonary side effects, including hypoxemia and hypercapnia, and calculated oxygenation indices (PaCO2-PETCO2) were worse than in MKB. One animal died after induction with EMM. The CII provided surgical anesthesia in 7 of 10 animals in MKB and in 9 of 9 animals in EMM for 120 min. In conclusion, the MKB induction protocol had advantages for prolonged anesthesia in impala with significantly less cardiopulmonary depression compared to EMM. The comparably decreased anesthetic depth could easily be adjusted by an increase of the CII.
Asunto(s)
Analgésicos/farmacología , Anestésicos Intravenosos/farmacología , Antílopes , Hipnóticos y Sedantes/farmacología , Analgésicos/administración & dosificación , Periodo de Recuperación de la Anestesia , Anestésicos Intravenosos/administración & dosificación , Animales , Butorfanol/administración & dosificación , Butorfanol/farmacología , Esquema de Medicación , Quimioterapia Combinada , Etorfina/administración & dosificación , Etorfina/farmacología , Femenino , Hipnóticos y Sedantes/administración & dosificación , Ketamina/administración & dosificación , Ketamina/farmacología , Medetomidina/administración & dosificación , Medetomidina/farmacología , Midazolam/administración & dosificación , Midazolam/farmacologíaRESUMEN
There is a growing necessity to perform long-term anesthesia in wildlife, especially antelope. The costs and logistics of transporting wildlife to veterinary practices make surgical intervention a high-stakes operation. Thus there is a need for a field-ready total intravenous anesthesia (TIVA) infusion to maintain anesthesia in antelope. This study explored the feasibility of an etorphine-ketamine-medetomidine TIVA for field anesthesia. Ten wild-caught, adult impala ( Aepyceros melampus ) were enrolled in the study. Impala were immobilized with a standardized combination of etorphine (2 mg) and medetomidine (2.2 mg), which equated to a median (interquartile range [IQR]) etorphine and medetomidine dose of 50.1 (46.2-50.3) and 55.1 (50.8-55.4) µg/kg, respectively. Recumbency was attained in a median (IQR) time of 13.9 (12.0-16.5) min. Respiratory gas tensions, spirometry, and arterial blood gas were analyzed over a 120-min infusion. Once instrumented, the TIVA was infused as follows: etorphine at a variable rate initiated at 40 µg/kg per hour (adjusted according to intermittent deep-pain testing); ketamine and medetomidine at a fixed rate of 1.5 mg/kg per hour and 5 µg/kg per hour, respectively. The etorphine had an erratic titration to clinical effect in four impala. Arterial blood pressure and respiratory and heart rates were all within normal physiological ranges. However, arterial blood gas analysis revealed severe hypoxemia, hypercapnia, and acidosis. Oxygenation and ventilation indices were calculated and highlighted possible co-etiologies to the suspected etorphine-induced respiratory depression as the cause of the blood gas derangements. Impala recovered in the boma post atipamezole (13 mg) and naltrexone (42 mg) antagonism of medetomidine and etorphine, respectively. The etorphine-ketamine-medetomidine TIVA protocol for impala may be sufficient for field procedures of up to 120-min duration. However, hypoxemia and hypercapnia are of paramount concern and thus oxygen supplementation should be considered mandatory. Other TIVA combinations may be superior and warrant further investigation.
Asunto(s)
Anestesia Intravenosa/veterinaria , Antílopes , Etorfina/farmacología , Ketamina/farmacología , Medetomidina/farmacología , Analgésicos no Narcóticos/administración & dosificación , Analgésicos no Narcóticos/farmacología , Analgésicos Opioides/administración & dosificación , Analgésicos Opioides/farmacología , Anestésicos Disociativos/administración & dosificación , Anestésicos Disociativos/farmacología , Animales , Animales Salvajes , Esquema de Medicación , Etorfina/administración & dosificación , Ketamina/administración & dosificación , Medetomidina/administración & dosificaciónRESUMEN
Corn snakes are emerging models for animal colouration studies. Here, we focus on the Terrazzo morph, whose skin pattern is characterized by stripes rather than blotches. Using genome mapping, we discover a disruptive mutation in the coding region of the Premelanosome protein (PMEL) gene. Our transcriptomic analyses reveal that PMEL expression is significantly downregulated in Terrazzo embryonic tissues. We produce corn snake PMEL knockouts, which present a comparable colouration phenotype to Terrazzo and the subcellular structure of their melanosomes and xanthosomes is also similarly impacted. Our single-cell expression analyses of wild-type embryonic dorsal skin demonstrate that all chromatophore progenitors express PMEL at varying levels. Finally, we show that in wild-type embryos PMEL-expressing cells are initially uniformly spread before forming aggregates and eventually blotches, as seen in the adults. In Terrazzo embryos, the aggregates fail to form. Our results provide insights into the mechanisms governing colouration patterning in reptiles.
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Pigmentación de la Piel , Animales , Pigmentación de la Piel/genética , Serpientes/embriología , Serpientes/genética , Serpientes/metabolismo , Melanosomas/metabolismo , Regulación del Desarrollo de la Expresión Génica , Mutación , Cromatóforos/metabolismo , Fenotipo , Embrión no Mamífero/metabolismo , Análisis de la Célula Individual/métodos , Color , Piel/metabolismo , Piel/embriología , Piel/citologíaRESUMEN
Follicular atresia (FA) has been assumed to serve different functions in reptiles, e.g. helping to develop hierarchies, limiting clutch size, and regression of ovarian structures. Reproductive output is dependent on a balance between ovulations and FA. Excessive rates of FA may not only be detrimental for the survival of a population, but have also been associated with pathological conditions. In order to gain insights into the physiological and potentially pathological processes of FA, we performed a decriptive study on the morphological features of the ovaries in sexually mature female veiled chameleons (Chamaeleo calyptratus, VC). Of 60 clinically healthy female VC with continuous ovarian cycling and at least one confirmed cycle with FA over at least 1.5 years, 30 were selected for macroscopic evaluation of ovarian appearance and 7 were subjected to histology and immunohistology. While FA of previtellogenic follicles happened at a low rate, expected for a species with two germinal beds per ovary and polyautochronic reproductive pattern, atresia in the late vitellogenic stage affected entire generations of follicles, consequential to ovulatory failure. Histologically, no pathological processes were identified in any of the animals. Rather, three stages of FA (early, middle, late) were defined and vitellogenic follicles showed two distinct morphological types of FA: yolky and cystic. Yolky FA was found in 21/30 (70%) animals, while cystic FA co-occurred in 9/30 (30%) of the animals.
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Atresia Folicular , Lagartos , Femenino , Animales , Lagartos/fisiología , Reproducción/fisiología , Ovulación , OvarioRESUMEN
Two influential concepts in tissue patterning are Wolpert's positional information and Turing's self-organized reaction-diffusion (RD). The latter establishes the patterning of hair and feathers. Here, our morphological, genetic, and functional-by CRISPR-Cas9-mediated gene disruption-characterization of wild-type versus "scaleless" snakes reveals that the near-perfect hexagonal pattern of snake scales is established through interactions between RD in the skin and somitic positional information. First, we show that ventral scale development is guided by hypaxial somites and, second, that ventral scales and epaxial somites guide the sequential RD patterning of the dorsolateral scales. The RD intrinsic length scale evolved to match somite periodicity, ensuring the alignment of ribs and scales, both of which play a critical role in snake locomotion.
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Plumas , Somitos , Animales , Difusión , Cabello , LocomociónRESUMEN
Syngnathidae is the family of fish that includes sea horses, pipefish, and sea dragons. To date, only a single publication has described neoplasia in syngnathids, a fibrosarcoma of the brood pouch in an aquarium-reared lined sea horse (Hippocampus erectus). From 1998 until 2010, the Toronto Zoo submitted 172 syngnathids for postmortem; species included the spotted or yellow sea horse (Hippocampus kuda), the pot-bellied sea horse (Hippocampus abdominalis) and the weedy sea dragon (Phyllopteryx taeniolatus). Seven neoplasms and two neoplastic-like lesions were identified from these cases. Under light microscopy, the neoplasms had morphological characteristics of a cardiac rhabdomyosarcoma, renal adenocarcinoma, renal adenoma, renal round cell tumors, which were likely lymphomas, exocrine pancreatic carcinoma, and intestinal carcinoma. Of these neoplasms, four had clear evidence of metastasis: the pancreatic and intestinal carcinomas and both round cell tumors. As syngnathids are highly fastidious animals, they can be difficult to maintain in captivity. In order to improve their husbandry, preventative and palliative care, as well as treatment, it is important to investigate and document the types of diseases affecting syngnathids.
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Enfermedades de los Peces/patología , Neoplasias/veterinaria , Smegmamorpha , Animales , Femenino , Masculino , Neoplasias/patologíaRESUMEN
Serum protein electrophoresis has gained importance in avian medicine during the past decade. Interpretation of electrophoretic patterns should be based on species-specific reference intervals and the electrophoresis gel system. In this study, serum protein electrophoresis by using high-resolution agarose gels was performed on blood samples collected from 105 falcons, including peregrine falcons (Falco peregrinus), gyrfalcons (Falco rusticolus), saker falcons (Falco cherrug), red-naped shaheens (Falco pelegrinoides babylonicus), and hybrid falcons, that were submitted to the Dubai Falcon Hospital (Dubai, United Arab Emirates) between 2003 and 2006. Reference values were established in clinically healthy birds and compared with values from falcons infected with Aspergillus species (n = 32). Falcons with confirmed aspergillosis showed significantly lower prealbumin values, which is a novel finding. Prealbumin has been documented in many avian species, but further investigation is required to illuminate the diagnostic significance of this negative acute-phase protein.
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Aspergilosis/veterinaria , Enfermedades de las Aves/sangre , Proteínas Sanguíneas/química , Electroforesis en Gel de Agar/veterinaria , Falconiformes , Animales , Aspergilosis/microbiología , Femenino , Masculino , Factores Sexuales , Especificidad de la EspecieRESUMEN
The noninvasive technique of gonadal steroid metabolite measurement in feces for evaluation of reproductive activity has proven an effective and important tool for population management in various captive species, but has not yet been validated and used in reptile species. In this study, enzyme immunoassays (EIAs) were validated for the analysis of fecal samples from female veiled chameleons (Chamaeleo calyptratus) for estrogen (E2), testosterone (T), and progesterone (P) and their metabolites. High performance liquid chromatography and physiological methods (GnRH stimulation) were used for the validation of the assays. Biological events, such as skin color changes indicative of ovarian activity and oviposition, correlated with the cyclical pattern of E2, T and P metabolites in feces over a period of two reproductive cycles. This is the first study to report frequent longitudinal measurements of fecal hormone levels by EIA in a reptile species.
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Estradiol/análisis , Heces/química , Técnicas para Inmunoenzimas/veterinaria , Lagartos/fisiología , Progesterona/análisis , Testosterona/análisis , Animales , Femenino , Técnicas para Inmunoenzimas/métodosRESUMEN
Abnormal behavior in nonhuman primates is oftentimes prematurely blamed on certain conditions, in the case of captive non-human primates, readily so on their husbandry, largely ignoring the underlying pathophysiological processes in the brain. Each life history shapes an individual's predisposition to develop or resist the development of a psychopathological disorder, which manifests itself in abnormal behavior when triggered by certain situations or conditions. In order to sustainably address the symptoms of psychopathologies, therapeutic approaches must be based on a structured, comprehensive diagnostic procedure, including behavioral and functional analyses, research into life history, and personality assessment..
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Crianza de Animales Domésticos , Conducta Animal , Bienestar del Animal , Animales , Primates/fisiologíaRESUMEN
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.
Asunto(s)
Lagartos/metabolismo , Lagartos/fisiología , Reproducción/fisiología , Animales , Estradiol/metabolismo , Femenino , Técnicas para Inmunoenzimas , Imagen por Resonancia Magnética , Oviposición/fisiología , Progesterona/metabolismo , Testosterona/metabolismoRESUMEN
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.
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Lagartos/metabolismo , Lagartos/fisiología , Reproducción/fisiología , Animales , Estradiol/metabolismo , Femenino , Técnicas para Inmunoenzimas , Imagen por Resonancia Magnética , Ovulación/fisiología , Progesterona/metabolismo , Testosterona/metabolismoRESUMEN
OBSERVATIONS: A 26-year-old male white rhinoceros (Ceratotherium simum), weighing approximately 2000 kg was anesthetized for an exploratory celiotomy. Sedation was achieved with intramuscular butorphanol (0.04 mg kg(-1)) and detomidine (0.025 mg kg(-1)) and induction of anesthesia with intravenous glyceryl guaiacolate (50 g) and three intravenous boluses of ketamine (200 mg, each); the trachea was then intubated and anesthesia maintained with isoflurane in oxygen using a circle breathing system. Positioning in dorsal recumbency for the surgery and later in sternal recumbency for the recovery represented challenges that added to the prolonged anesthesia time and surgical approach to partially correct an impaction. The rhinoceros recovered uneventfully after 10.4 hours of recumbency. CONCLUSIONS: Anesthetic management for an exploratory celiotomy with a midline approach is possible in rhinoceroses, although planning and extensive staff support is necessary to adequately position the patient.
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Anestesia/veterinaria , Cólico/veterinaria , Laparotomía/veterinaria , Perisodáctilos/cirugía , Analgésicos Opioides , Anestesia/métodos , Anestesia por Inhalación/veterinaria , Anestésicos , Anestésicos por Inhalación , Animales , Animales de Zoológico/cirugía , Butorfanol , Cólico/cirugía , Tratamiento de Urgencia/veterinaria , Imidazoles , Intubación Intratraqueal/veterinaria , Isoflurano , Ketamina , Laparotomía/métodos , Masculino , Medicación Preanestésica/veterinariaRESUMEN
Cerebral xanthomatosis was diagnosed in three female green water dragons (Physignathus cocincinus), all of which presented with progressive neurologic signs. No antemortem evidence for xanthomatosis was identified, but on postmortem examination cholesterol granulomas, composed of cholesterol clefts surrounded by macrophages and multinucleated giant cells, were found in the forebrain of each animal and were associated with significant displacement and pressure on the adjacent brain. Although the cause of xanthomatosis in these animals is unknown, nutrition and trauma may be involved in the pathogenesis of this condition. Cerebrum, cholesterol, green water dragon, Physignathus cocincinus, xanthoma.
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Encefalopatías/veterinaria , Cerebro/patología , Lagartos , Xantomatosis/veterinaria , Animales , Encefalopatías/patología , Ventrículos Cerebrales/patología , Femenino , Xantomatosis/patologíaRESUMEN
Courtship behaviour of tortoises includes biting, ramming, chasing, same-sex sexual behaviour, and it commonly is excessive in European tortoise species kept as pets. As a result, males are kept individually. To assess the effect of orchiectomy on excessive courtship behaviour in European tortoises, 50 tortoises (Testudo graeca , T hermanni and T marginata ) underwent endoscopically assisted orchiectomy from April through September 2013 to 2017. Statistical analyses were performed in relation to species, body mass, testicular size and season and owners were invited to fill out a follow-up questionnaire. Body mass of the tortoises ranged from 334 to 2645 g (mean 1056 g) and the age from 5 to estimated 60 years. Testicular length ranged from 1.4 to 7.0 cm (mean 2.7 cm) and testicular mass from 0.6 to 12.6 g (mean 3.9 g). A complete or partial reduction (allowing group-housing) of the excessive courtship behaviour was noted by 95 per cent of owners and 59 per cent of the owners reported a noticeable change of behaviour within a month of surgery. Given the seasonal variation in testicular size, the best period for castrations in male European tortoises is shortly after brumation (April, May), when testes are proportionally smaller.