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PubMed1989

Comparative immunohistochemical study of the gastroenteropancreatic endocrine system of three reptiles.

The gastroenteropancreatic (GEP) endocrine system of three reptiles, Testudo graeca, Mauremys caspica, and Lacerta lepida, was investigated by means of immunocytochemistry. Single and double immunostaining methods have demonstrated immunoreactivity for insulin, glucagon, pancreatic polypeptide (PP), somatostatin, serotonin, and peptide tyrosine tyrosine (PYY) in endocrine cells of the pancreas of the reptiles studied. Islet-like structures with insulin-immunoreactive (IR) cells surrounded by glucagon-IR cells were observed only in the splenic portion of the pancreas of M. caspica. Occasionally, somatostatin- and PP-IR cells were associated with glucagon-containing cells. Endocrine cells were also observed in the excretory ducts of the exocrine glands. Serotonin, bombesin, neurotensin, gastrin, glucagon, somatostatin, PYY, and insulin were demonstrated immunocytochemically in open-type GEP cells of the digestive tract of the animals studied. Serotonin, somatostatin, and glucagon-immunoreactive cells were the most abundant endocrine cell types. In L. lepida, PP- and peptide tyrosine tyrosine-immunoreactive cells were also frequently observed. Cells containing cholecystokinin, gastric inhibitory peptide, met- and leu-enkephalin, motilin, secretin, and vasoactive intestinal peptide could not be detected. The present work demonstrates that the reptilian GEP endocrine system is a complex structure containing most of the regulatory peptides similar in structure to those found in higher vertebrates.

Animals↗
PubMed2004

Flavor aversion learning induced by lithium chloride in reptiles but not in amphibians.

Flavor aversion learning occurs when digestive illness follows ingestion of a novel food. Such learning has been shown to exist in mammals and birds. In this experiment, we looked for flavor aversion learning in amphibians (Bufo paracnemis, Pachytriton breviceps) and reptiles (Basiliscus vitattus, B. basiliscus, Eumeces schneideri, Mabuya multifasciata). After intake of the novel food, the animals received i.p. injection of either lithium chloride (LiCl), an effective illness inducer, or a saline solution. A week later, the LiCl injection had not affected the food intake of the amphibians whereas in the lizards it had produced a strong aversion to the flavor of the novel food. These results are consistent with the hypothesis that specific mental capacities emerged with reptiles.

Amphibians↗
PubMed2004

Lung collapse among aquatic reptiles and amphibians during long-term diving.

Numerous aquatic reptiles and amphibians that typically breathe both air and water can remain fully aerobic in normoxic (aerated) water by taking up oxygen from the water via extrapulmonary avenues. Nevertheless, if air access is available, these animals do breathe air, however infrequently. We suggest that such air breathing does not serve an immediate gas exchange function under these conditions, nor is it necessarily related to buoyancy requirements, but serves to keep lungs inflated that would otherwise collapse during prolonged submergence. We also suggest that lung deflation is routine in hibernating aquatic reptiles and amphibians in the northern portions of their ranges, where ice cover prevents surfacing for extended periods.

Amphibians↗
PubMed2006

Renal pathology in reptiles.

The class of Reptilia varies widely. Both the gross morphology and microscopic anatomy of the kidneys are specific for each species. In each species of reptile, the physiology of the renal system has adapted to the specific conditions of life, including, among other factors, the type of food, environmental temperature, and the availability of water. The pathology of the kidneys in reptiles has been poorly studied, but in recent years a number of investigators have specifically studied reptilian renal pathology.

Animals↗
PubMed2006

Common procedures in reptiles and amphibians.

Reptiles and amphibians continue to be popular as pets in the United States and throughout the world. It therefore behooves veterinarians interested in caring for these exotic species to continually gather knowledge concerning both their proper husbandry and the conditions that require medical and/or surgical intervention. This article covers husbandry, physical examination, and clinical and diagnostic techniques in an effort to present guidelines for the evaluation of the reptile or amphibian patient. Gathering clinical data will aid veterinarians in arriving at the proper diagnosis,increasing the chances of success with treatment protocols, and educating the clients in proper nutrition and husbandry for their pets.

Amphibians↗
PubMed2004

Evolutionary insights into the regulation of courtship behavior in male amphibians and reptiles.

Comparative studies of species differences and similarities in the regulation of courtship behavior afford an understanding of evolutionary pressures and constraints shaping reproductive processes and the relative contributions of hormonal, genetic, and ecological factors. Here, we review species differences and similarities in the control of courtship and copulatory behaviors in male amphibians and reptiles, focusing on the role of sex steroid hormones, the neurohormone arginine vasotocin (AVT), and catecholamines. We discuss species differences in the sensory modalities used during courtship and in the neural correlates of these differences, as well as the value of particular model systems for neural evolution studies with regard to reproductive processes. For example, in some genera of amphibians (e.g., Ambystoma) and reptiles (e.g., Cnemidophorus), interspecific hybridizations occur, making it possible to compare the ancestral with the descendant species, and these systems provide a window into the process of behavioral and neural evolution as well as the effect of genome size. Though our understanding of the hormonal and neural correlates of mating behavior in a variety of amphibian and reptilian species has advanced substantially, more studies that manipulate hormone or neurotransmitter systems are required to assess the functions of these systems.

Amphibians↗
PubMed2005

Salmonella enterica isolates from faeces of domestic reptiles and a study of their antimicrobial in vitro sensitivity.

From October 2001 to February 2002, the faecal samples of 305 reptiles (165 saurians, 99 ophidians and 41 chelonians) were bacteriologically examined to detect Salmonella enterica. S. enterica was isolated from 73 (23.93%) faecal samples including 44 (60.27%) samples collected from saurians, 15 (20.55%) from chelonians and 14 (19.18%) from ophidians; considering the number of samples taken for each reptile group, S. enterica was isolated from the 36.58% of chelonians, 26.66% of saurians and 14.14% of ophidians. The isolates were distributed among 38 serotypes. Sixty-nine (94.52%) isolates were resistant to erythromycin. About one-third of the isolates was resistant to sulfisoxazole (35.61%), gentamycin (32.88%), amoxycillin (31.51%) and ampicillin (27.40%). All but one of the isolates were sensitive to chloramphenicol. A high percentages of isolates were sensitive to enrofloxacin (84.93%), nitrofurantoin (80.82%), trimethoprim (76.71%) and tetracycline (75.34%).

Animals↗
PubMed2004

Phylogenetic relationships among amphisbaenian reptiles based on complete mitochondrial genomic sequences.

Complete mitochondrial genomic sequences are reported from 12 members in the four families of the reptile group Amphisbaenia. Analysis of 11,946 aligned nucleotide positions (5797 informative) produces a robust phylogenetic hypothesis. The family Rhineuridae is basal and Bipedidae is the sister taxon to the Amphisbaenidae plus Trogonophidae. Amphisbaenian reptiles are surprisingly old, predating the breakup of Pangaea 200 million years before present, because successive basal taxa (Rhineuridae and Bipedidae) are situated in tectonic regions of Laurasia and nested taxa (Amphisbaenidae and Trogonophidae) are found in Gondwanan regions. Thorough sampling within the Bipedidae shows that it is not tectonic movement of Baja California away from the Mexican mainland that is primary in isolating Bipes species, but rather that primary vicariance occurred between northern and southern groups. Amphisbaenian families show parallel reduction in number of limbs and Bipes species exhibit parallel reduction in number of digits. A measure is developed for comparing the phylogenetic information content of various genes. A synapomorphic trait defining the Bipedidae is a shift from the typical vertebrate mitochondrial gene arrangement to the derived state of trnE and nad6. In addition, a tandem duplication of trnT and trnP is observed in Bipes biporus with a pattern of pseudogene formation that varies among populations. The first case of convergent rearrangement of the mitochondrial genome among animals demonstrated by complete genomic sequences is reported. Relative to most vertebrates, the Rhineuridae has the block nad6, trnE switched in order with the block cob, trnT, trnP, as they are in birds.

Animals↗
PubMed1998

An outbreak of salmonellosis among children attending a reptile exhibit at a zoo.

OBJECTIVE: In January 1996, an outbreak of diarrhea caused by Salmonella Enteritidis occurred in children attending a Komodo dragon exhibit at a metropolitan zoo. We sought to determine the extent of the outbreak and mode of transmission. STUDY DESIGN: A case-control study was conducted. Controls were randomly selected from zoo membership lists and matched to patients by age group and date of exhibit visit. RESULTS: Of 65 patients identified, 39 had confirmed and 26 had suspected cases. The median age was 7 years (range, 3 months to 48 years); 55% were enrolled in the case-control study. No patients and two (4%) controls reported touching a dragon; however, 83% of patients but only 52% of controls touched the wooden barrier that surrounded the dragon pen (odds ratio = 4.0, 95% CI 1.2 to 13.9). Washing hands at the zoo after visiting the dragons was highly protective (OR = 0.14, 95% CI 0.03 to 0.7). Cultures from the patients, one dragon, and the exhibit barriers yielded Salmonella Enteritidis, phage type 8. On the basis of an attack rate of 4.3% among exhibit attendees under 13 years old on whom data were collected, we estimate that 315 additional cases of salmonellosis occurred among visitors in this age group. CONCLUSION: This large outbreak demonstrates the importance of environmental contamination in the transmission of Salmonella from reptiles, and the protective value of hand washing. Recommendations regarding reptile exhibits and reptilian pets should emphasize this indirect route.

Adolescent↗
PubMed2001

The circadian system of reptiles: a multioscillatory and multiphotoreceptive system.

Many parameters exhibited by organisms show daily fluctuations that may persist when the organisms are held in constant environmental conditions. Rhythms that persist in constant conditions with a period close to 24 h are called circadian. Although nowadays most research in this field is focused on the molecular and genetic aspects--and therefore mostly on two animal models (Drosophila and mouse)--the study of alternative animal models still represent a useful approach to understanding how the vertebrate circadian system is organized, and how this fascinating time-keeping system has changed throughout the evolution of vertebrates. The present paper summarizes the current knowledge of the circadian organization of Reptiles. The circadian organization of reptiles is multioscillatory in nature. The retinas, the pineal, and the parietal eye (and, possibly, the suprachiasmatic nuclei of the hypothalamus, SCN) contain circadian clocks. Of particular interest is the observation that the role these structures play in the circadian organization varies considerably among species and within the same species in different seasons. Another remarkable feature of this class is the redundancy of circadian photoreceptors: retinas of the lateral eyes, pineal, parietal eye, and the brain all contain photoreceptors.

Animals↗
PubMed2000

The biology of some intraerythrocytic parasites of fishes, amphibia and reptiles.

Fishes, amphibia and reptiles, the ectothermic vertebrates, are hosts for a variety of intraerythrocytic parasites including protists, prokaryotes, viruses and structures of uncertain status. These parasites may experience host temperature fluctuations, host reproductive strategies, population genetics, host habitat and migratory behaviour quite unlike those of endothermic hosts. Few blood infections of fishes, amphibia and reptiles have proven pathogenicity, in contrast to the many intraerythrocytic parasites of mammals and some birds which harm their hosts. Although not given the attention afforded to intraerythrocytic parasites of endotherms, those of ectotherms have been studied for more than a century. This review reports on the diversity, general biology and phylogeny of intraerythrocytic parasites of ectotherms. The existence of taxonomic confusion is emphasized and the main taxonomic features of most of the 23 better characterized genera, particularly the kinetoplastid and apicomplexan protists, are summarized. Transmission of protistan infections of aquatic ectotherms is also discussed. Leeches can transfer sporozoties or merozoites to the vertebrate host during feeding. Dormant sporozoites of Lankesterella may permit transmission of species of this genus between vertebrates by predation. The fish haemogregarine, Haemogregarina bigemina, probably has gnathiid isopods, rather than leeches, as its definitive hosts. Hepatozoon spp. in aquatic hosts, and Progarnia of caiman, may also use invertebrate hosts other than leeches. Protistan infections of terrestrial or semi-terrestrial hosts are transmitted by a variety of arthropods, or, in some cases, leeches, contaminated paratenic hosts, or sporocysts free in water. Transfer of protists between vertebrates by predation and congenitally may also occur. The biology of the host cells of these infections, the red blood cells of ectotherm vertebrates, is summarized and compared with that of mammalian erythrocytes. Erythropoiesis, the nature of the surface molecules (especially the possible existence of a major histocompatibility complex), the haemoglobins, and the shape and size of erythrocytes are discussed. The exoerythrocytic sites in which protists, prokaryotes, viruses and structures of uncertain status exist before erythrocyte entry are described. Tissue merogony, tissue cysts and invasion of the white cell series occur in a variety of protistan infections. Intraerythrocytic stages of protistan infections are also discussed, including modes of entry to erythrocytes, survival mechanisms, and multiplication. The impact of infection on host populations is difficult to assess, in part because there is no agreement in the literature on the criteria used to evaluate parasite-induced cost to the host. Almost all studies have been on haemogregarine and Plasmodium infections in, mainly, lizards, but also fishes and snakes. Some infections may be responsible for mortality in their hosts, but hosts themselves may be short-lived, or have a limited ability to recover from infection.

Amphibians↗
PubMed1987

Reptiles.

Basic techniques that will allow the clinician to properly evaluate the ill reptile are discussed. How to take a complete history and a systematic approach to physical examination are emphasized. Techniques for collection of samples for clinical evaluation and selection of drugs for treating ill reptiles are reviewed briefly.

Animal Diseases↗
PubMed2003

Two new avian mitochondrial genomes (penguin and goose) and a summary of bird and reptile mitogenomic features.

We report complete mitochondrial (mt) genomes for a penguin (little blue, Eudyptula minor) and a goose (greater white-fronted, Anser albifrons). A revised annotation of avian and reptile mt genomes has been carried out, which improves consistency of labeling gene start and stop positions. In conjunction with this, a summary of mt gene features is presented and a number of conserved patterns and interesting differences identified. The protein-coding genes from the two new genomes were analysed together with those from 17 other birds plus outgroup (reptile) taxa. The unrooted amino acid tree from 19 avian genomes was locally stable with many high bootstrap values using several maximum likelihood methods. In particular, Anseriformes (goose and duck) grouped strongly with Galliformes (chicken) to form Gallianseres, while the penguin paired firmly with the stork. The position where the outgroup joined the avian tree varied with the combination of outgroup taxa used. The three best supported positions of the root were passerine, but the traditional rooting position between paleognaths and neognaths could not be excluded.

Animals↗
PubMed1999

Granin proteins (chromogranin A and secretogranin II C23-3 and C26-3) in the intestine of reptiles.

The occurrence, distribution and the possible cellular co-localizations of chromogranin A (CgA) and of two synthetic secretogranin II-peptides (SgIIC23-3 and SgIIC26-3) with several enteric neuropeptides and serotonin have been investigated immunohistochemically in turtles, lizards and snakes. The distribution of CgA-immunoreactivity was restricted only to the enteroendocrine cells in all the reptiles studied. SgII-immunoreactivity--absent in turtle--revealed nerve cells and fibers, besides enteroendocrine cells in lizard and snake guts. Moreover, the two antisera (C23-3 and C26-3) raised against the different regions of the SgII-molecule yielded distinct distribution patterns of immunoreactivity both in the lizard and snake organs. Small amounts of enteric serotonin cells co-stored CgA or SgIIC23-3 in lizards and snakes and only SgIIC26-3-peptide in snakes. CgA was found co-stored with somatostatin in a few enterocytes of the turtle duodenum. In the same gut segment of lizards and throughout the snake organ, neurotensin and the SgIIC23-3-peptide co-existed in a small number of endocrine cells. The pancreatic polypeptide-containing cells were devoid of immunoreactivity both for CgA and SgII. Bombesin immunopositive cells were absent throughout the intestines of the reptiles investigated. The above findings entirely support the heterogenous distribution of granins in neuroendocrine organs and tissues and also within the same neuroendocrine cell population. They further support the concept of a good conservation of granins during phylogeny.

Animals↗
PubMed2001

Fish, amphibian, and reptile analgesia.

Pain perception and appropriate behavioral responses are important for survival. The conservation of the opioid ligand and receptor suggests evolution of opioid receptors mediating antinociception throughout vertebrate phylogeny. Fish, amphibians, and reptiles have appropriate neurologic components, display the appropriate behavior in response to a painful stimulus, and possess antinociceptive mechanisms to modulate pain. Because pain perception in these species is therefore likely to be analogous to that of mammals, invasive and painful procedures should always be accompanied by appropriate analgesia and anesthesia. Although specific doses have not been established in clinical trials, clinicians should attempt to provide lower vertebrates with appropriate analgesia during painful procedures. Further experimental and clinical investigations are necessary to expand the current veterinary literature in the area of pain and analgesia in lower vertebrates such as fish, amphibians, and reptiles.

Amphibians↗
PubMed1999

Clinical evaluation of reptiles.

A detailed history and physical examination usually provides the veterinarian with a list of possible differential diagnoses and indicates which further investigations may be necessary to make a definitive diagnosis. Radiography, ultrasonography, endoscopy, hematology, blood biochemistry, and microbiological and parasitologic investigations are all proven techniques that are used extensively in reptile medicine. A logical case workup enables the clinician to make a previously elusive reptile diagnosis and offers this interesting group of animals veterinary services comparable with that already expected for more domesticated pets.

Animal Diseases↗
PubMed1999

Designing environments for captive amphibians and reptiles.

Environments for captive amphibians and reptiles play a critical role in their long-term health, and veterinarians need to be informed of the requirements of various species when evaluating the causes of disease. Enclosure size, substrates, landscaping, heating, lighting, and relative humidity are the areas of primary concern when designing vivaria. Two different approaches are used when keeping amphibians and reptiles, depending primarily on the size of the species maintained: a laboratory animal-type system and naturalistic vivarium system. The latter places more emphasis on simulating essential elements of natural habitats and on aesthetic appeal of the display.

Amphibians↗
PubMed1999

Nutrition of captive reptiles.

In reptile practice, most nutritional problems arise from improper husbandry, including poor feeding management and provision of imbalanced diets. Each reptile species has its own requirements for temperature and humidity, space and social interaction, lighting, and habitat components. Failure, to provide these requirements often results in failure to thrive and secondary nutritional disorders. Common dietary problems include deficiencies of energy, calcium, vitamin D3, vitamin A, and fiber.

Animal Diseases↗