Academic literature on the topic 'Bearded dragons (Reptiles) as pets'

Reptiles are popular as pets and it is, therefore, important to understand how different aspects of housing and husbandry impact on their behaviour and welfare. One potential cause of stress in captive reptiles is interaction with humans; in particular, the effect of handling. However, little research on handling has been carried out with reptiles, particularly relating to the type of gentle handling likely to be experienced by pet animals. The aim of this study was therefore to determine whether the amount of time that bearded dragons (Pogona vitticeps), a commonly kept pet species, experienced gentle handling induced no or differing levels of anxiety, as reflected in their subsequent behavioural response to novelty. We found that there appeared to be a mildly aversive effect of handling time on subsequent behavioural response to novelty. Longer durations of handling (5 min or 15 min) appeared to increase anxiety-related behaviour, with handled animals showing more frequent tongue flicking behaviour when they experienced a novel environment and reduced time spent in close proximity to a novel object. These results suggest that handling bearded dragons, even in a gentle way, may increase their anxiety. However, it is not yet known whether animals may habituate to handling for longer periods if provided with additional experience.

Reptiles are one of the most popular exotic pets in the world, with over a third of all described species currently being traded. However, the most commonly available reptiles are typically non-threatened, captive-bred, and/or domestically obtained, which means they are also largely unregulated and unmonitored, resulting in a large portion of the reptile pet trade remaining unknown. In this study, the past, current, and future trends of the most popular reptiles in the pet trade were examined. Google Trends was used to determine the global popularity of the most popular pets from 2004 to 2020 and compared to the results from an online survey sent to individuals involved in the reptile trade. The most popular pets from the previous five years were also compared globally across regions and countries. The results determined that the most popular reptile species during the last decade is by far bearded dragons, followed by ball pythons and leopard geckos. Although the survey results were similar when asked what the top reptiles were, most respondents named ball pythons as the most popular reptile. However, when asked what reptiles had lost the most popularity during the previous decade, the survey respondents named green iguanas, Burmese pythons, chameleons, red-eared sliders, and green anoles, concurring with what was found with Google Trends. The reptiles thought to be more popular in the upcoming decade by the survey participants were blue-tongued skinks, tegus, uromastyx, crested geckos, and ball pythons—most of which did indeed show an increase in popularity during the last decade, as indicated with Google Trends. The results from Google Trends demonstrated that ball pythons and crested geckos have increased their popularity more than any other reptile in the last two decades. Reptile popularity also differed between countries, with bearded dragons the most popular reptile in Australia, Western Europe, the U.S., and Canada. Leopard geckos were the most popular reptile in Italy and Turkey, and ball pythons were the reptile of choice in Mexico, Indonesia, and India. The general finding of this study is that the reptiles declining in popularity were mostly wild-caught or restricted due to regulations, while current and future species were captive-bred and available in many varieties or morphs. The most popular species were also docile, medium-sized, and easy to handle, with relatively simple care requirements. This study demonstrates that Google Trends can be a useful tool for determining relative popularity among reptiles, or any other pet group, with results closely mirroring those obtained through direct surveying of people involved in the pet trade. However, unlike surveys, this analysis is quick, quantifiable, and can show what is popular and in-demand not only at the global level but at much finer scales. Thus, Google Trends can be a valuable tool in many research applications, especially in topics that may otherwise be difficult to monitor and quantify.

ABSTRACT Metarhizium viride has been associated with fatal systemic mycoses in chameleons, but subsequent data on mycoses caused by this fungus in reptiles are lacking. The aim of this investigation was therefore to obtain information on the presence of M. viride in reptiles kept as pets in captivity and its association with clinical signs and pathological findings as well as improvement of diagnostic procedures. Beside 18S ribosomal DNA (rDNA) (small subunit [SSU]) and internal transcribed spacer region 1 (ITS-1), a fragment of the large subunit (LSU) of 28S rDNA, including domain 1 (D1) and D2, was sequenced for the identification of the fungus and phylogenetic analysis. Cultural isolation and histopathological examinations as well as the pattern of antifungal drug resistance, determined by using agar diffusion testing, were additionally used for comparison of the isolates. In total, 20 isolates from eight inland bearded dragons ( Pogona vitticeps ), six veiled chameleons ( Chamaeleo calyptratus ), and six panther chameleons ( Furcifer pardalis ) were examined. Most of the lizards suffered from fungal glossitis, stomatitis, and pharyngitis or died due to visceral mycosis. Treatment with different antifungal drugs according to resistance patterns in all three different lizard species was unsuccessful. Sequence analysis resulted in four different genotypes of M. viride based on differences in the LSU fragment, whereas the SSU and ITS-1 were identical in all isolates. Sequence analysis of the SSU fragment revealed the first presentation of a valid large fragment of the SSU of M. viride . According to statistical analysis, genotypes did not correlate with differences in pathogenicity, antifungal susceptibility, or species specificity.

Viral pathogens are being increasingly described in association with mass morbidity and mortality events in reptiles. However, our knowledge of reptile viruses remains limited. Herein, we describe the meta-transcriptomic investigation of a mass morbidity and mortality event in a colony of central bearded dragons (Pogona vitticeps) in 2014. Severe, extensive proliferation of the respiratory epithelium was consistently found in affected dragons. Similar proliferative lung lesions were identified in bearded dragons from the same colony in 2020 in association with increased intermittent mortality. Total RNA sequencing identified two divergent DNA viruses: a reptile-infecting circovirus, denoted bearded dragon circovirus (BDCV), and the first exogeneous reptilian chaphamaparvovirus—bearded dragon chaphamaparvovirus (BDchPV). Phylogenetic analysis revealed that BDCV was most closely related to bat-associated circoviruses, exhibiting 70% amino acid sequence identity in the Replicase (Rep) protein. In contrast, in the nonstructural (NS) protein, the newly discovered BDchPV showed approximately 31%–35% identity to parvoviruses obtained from tilapia fish and crocodiles in China. Subsequent specific PCR assays revealed BDCV and BDchPV in both diseased and apparently normal captive reptiles, although only BDCV was found in those animals with proliferative pulmonary lesions and respiratory disease. This study expands our understanding of viral diversity in captive reptiles.

Abstract Objective This study determined the passage time and phage propagation time of a salmonella specific phage, Felix O1, in bearded dragons, based on reisolation from cloacal swabs and faecal samples following oral administration, as a possible tool for reducing the zoonotic risk of salmonella from pet reptiles. An application scheme for this phage in bearded dragons was developed. Material and methods Ten healthy bearded dragons (Pogona vitticeps) were used in the study. The pH tolerance of the phage was tested and drugs were used to evaluate their influence on the gastric pH of the reptiles. After pH adjustment, the phage was administered orally for 12 consecutive days. Over 60 days, swabs were taken from the cloaca and examined for the presence of phages using culture and PCR. Furthermore, faecal samples were collected for phage quantification. Results Felix O1 displayed no activity at pH below 2.8. A calcium- and magnesium carbonate buffer induced an appropriate gastric pH increase for 30 minutes. Phages were reisolated for up to 24 days (mean shedding: 19 days) after last administration. Titres between 105 and 107 plaque forming units/g faeces were detected. The animals did not show any clinical signs related to phage application. Conclusion and clinical relevance The study provides first results on oral administration, passage time, and reisolation of a phage in reptiles. It could be shown that the phage was able to replicate in the intestine, and was shed for a prolonged period and therefore could potentially contribute to a reduction of salmonella shedding.

In birds and oviparous reptiles, hatching is often a lengthy and exhausting process, which commences with pipping followed by lung clearance and pulmonary ventilation. We examined the composition of pulmonary surfactant in the developing lungs of the chicken, Gallus gallus, and of the bearded dragon, Pogona vitticeps. Lung tissue was collected from chicken embryos at days 14, 16, 18 (prepipped), and 20(postpipped) of incubation and from 1 day and 3 wk posthatch and adult animals. In chickens, surfactant protein A mRNA was detected using Northern blot analysis in lung tissue at all stages sampled, appearing relatively earlier in development compared with placental mammals. Chickens were lavaged at days 16, 18, and 20 of incubation and 1 day posthatch, whereas bearded dragons were lavaged at day 55, days 57–60 (postpipped), and days 58–61 (posthatched). In both species, total phospholipid (PL) from the lavage increased throughout incubation. Disaturated PL (DSP) was not measurable before 16 days of incubation in the chick embryo nor before 55 days in bearded dragons. However, the percentage of DSP/PL increased markedly throughout late development in both species. Because cholesterol (Chol) remained unchanged, the Chol/PL and Chol/DSP ratios decreased in both species. Thus the Chol and PL components are differentially regulated. The lizard surfactant system develops and matures over a relatively shorter time than that of birds and mammals. This probably reflects the highly precocial nature of hatchling reptiles.

Chromatophoromas are neoplasms that develop from the dermal pigment-bearing and light-reflecting cells (chromatophores) in the skin of reptiles, fish, and amphibians. Seventeen cutaneous chromatophoromas were identified from 851 bearded dragon submissions (2%) to a private diagnostic laboratory in a 15-y period. No sex predilection was found. Ages ranged from 9 mo to 11 y. Chromatophoromas most commonly were single, raised, variably pigmented masses or pigmented scales on the trunk, and less commonly the extremities or head. Microscopically, iridophoromas, melanophoromas, mixed chromatophoromas, and nonpigmented chromatophoromas were identified. Neoplasms were often ulcerated and invaded deep into the subcutis and muscle. Most commonly, nuclear atypia was mild-to-moderate, and mitotic count was low. Six neoplasms had abundant, periodic acid-Schiff–positive, mucinous stroma. Histologic examination was often adequate to diagnose chromatophoromas in bearded dragons given that 11 of 17 had some degree of pigmentation, although it was often scant. IHC for S100 and PNL2 could be helpful to diagnose poorly pigmented neoplasms. No lymphatic invasion or metastases at the time of excision were noted in any of the cases. Follow-up data were available for 6 cases, with no reports of recurrence or neoplasia-related death. Two cases had elevated mitotic counts and nuclear pleomorphism, which has been associated with metastasis in other reports of bearded dragon chromatophoromas. In general, it appears that aggressive surgical excision is often curative, but monitoring may be warranted for cases in which tumors had high mitotic count and nuclear pleomorphism.

Two central bearded dragons ( Pogona vitticeps), a 3-y-old male and a 5-y-old female, were diagnosed with different manifestations of lymphoma at the Kansas State Veterinary Diagnostic Laboratory between 2019 and 2020. The 3-y-old male was presented for postmortem evaluation and was in poor body condition. Microscopically, nearly all examined organs contained variable numbers of neoplastic round cells. Neoplastic cells in the stomach and liver had moderate immunoreactivity to CD3 consistent with multicentric T-cell lymphoma, and non-neoplastic lymphocytes infiltrating the stomach mass had strong immunoreactivity to Pax5. The 5-y-old female had an ulcerated oral mass located in the right lingual gingiva submitted as an excisional biopsy. Microscopically, the mass was composed of large numbers of neoplastic round cells in the epithelium and connective tissue that were strongly and diffusely positive for CD3 and frequently positive for Pax5, consistent with a dual-positive, localized, epitheliotropic T-cell lymphoma. Neoplastic and non-neoplastic lymphocytes did not stain with CD20 or CD79a. Neoplasms are increasingly reported as a cause of morbidity and mortality in reptiles. Our 2 cases illustrate various presentations of T-cell lymphoma and the effectiveness of CD3 and Pax5 immunohistochemistry in bearded dragons.

In this study, synchronous spontaneous, independent liver and gallbladder tumours were detected in a Bearded dragon (Pogona vitticeps). The multiple tumours consisted of intrahepatic cholangiocarcinoma as well as in situ adenocarcinoma and two adenomas of the gallbladder. The biliary epithelial cells and the cholangiocarcinoma showed membranous cross-immunoreactivity for claudin-7. The gallbladder epithelial cells, its adenoma and adenocarcinoma showed basolateral cross-reactivity for claudin-7. We think that the humanised anti-claudin-7 antibody is a good marker for the detection of different primary cholangiocellular and gallbladder tumours in Bearded dragons. The cholangiocytes, the cholangiocarcinoma, the endothelial cells of the liver and the epithelial cells and gallbladder tumours all showed claudin-5 cross-reactivity. The humanised anti-cytokeratin AE1–AE3 antibody showed cross-reactivity in the biliary epithelial cells, cholangiocarcinoma cells, epithelial cells and tumour cells of the gallbladder. It seems that this humanised antibody is a useful epithelial marker for the different neoplastic lesions of epithelial cells in reptiles. The humanised anti-α-smooth muscle actin (α-SMA) antibody showed intense cross-reactivity in the smooth muscle cells of the hepatic vessels and in the muscle layer of the gallbladder. The portal myofibroblasts, the endothelial cells of the sinusoids and the stromal cells of the cholangiocarcinoma and gallbladder tumours were positive for α-SMA. The antibovine anti-vimentin and humanised anti-Ki-67 antibodies did not show crossreactivity in the different samples from the Bearded dragon.

Invertebrate iridoviruses (IIVs), while mostly described in a wide range of invertebrate hosts, have also been repeatedly detected in diagnostic samples from poikilothermic vertebrates including reptiles and amphibians. Since iridoviruses from invertebrate and vertebrate hosts differ strongly from one another based not only on host range but also on molecular characteristics, a series of molecular studies and bioassays were performed to characterize and compare IIVs from various hosts and evaluate their ability to infect a vertebrate host. Eight IIV isolates from reptilian and orthopteran hosts collected over a period of six years were partially sequenced. Comparison of eight genome portions (total over 14 kbp) showed that these were all very similar to one another and to an earlier described cricket IIV isolate, thus they were given the collective name lizard–cricket IV (Liz–CrIV). One isolate from a chameleon was also subjected to Illumina sequencing and almost the entire genomic sequence was obtained. Comparison of this longer genome sequence showed several differences to the most closely related IIV, Invertebrate iridovirus 6 (IIV6), the type species of the genus Iridovirus, including several deletions and possible recombination sites, as well as insertions of genes of non-iridoviral origin. Three isolates from vertebrate and invertebrate hosts were also used for comparative studies on pathogenicity in crickets (Gryllus bimaculatus) at 20 and 30 °C. Finally, the chameleon isolate used for the genome sequencing studies was also used in a transmission study with bearded dragons. The transmission studies showed large variability in virus replication and pathogenicity of the three tested viruses in crickets at the two temperatures. In the infection study with bearded dragons, lizards inoculated with a Liz–CrIV did not become ill, but the virus was detected in numerous tissues by qPCR and was also isolated in cell culture from several tissues. Highest viral loads were measured in the gastro-intestinal organs and in the skin. These studies demonstrate that Liz–CrIV circulates in the pet trade in Europe. This virus is capable of infecting both invertebrates and poikilothermic vertebrates, although its involvement in disease in the latter has not been proven.

The genes in alpha ({u03B1})- and beta ({u03B2})- globin clusters constitute a functional haemoglobin molecule, crucial for oxygen transportation. In most fish and amphibians, {u03B1}- and {u03B2}-globin genes are located together, whereas in amniotes (birds and mammals), there are two distinct clusters. Several complex models have been proposed to explain the evolution of these gene clusters. However, there was a lack of data for key positions in amniote phylogeny to discern which one was most parsimonious. Therefore, the main aims of this project were to characterise {u03B1}- and {u03B2}-globin clusters and their regulatory regions in a monotreme Ornithorhynchus anatinus (Australian duck-billed platypus) and two reptilian species Pogona vitticeps (Australian bearded dragon) and Anolis carolinensis (green anole lizard), to gain insight into globin loci evolution. This thesis is presented as a collection of research papers covering each topic, and a review and discussion that summarises my research. The first paper (Chapter 2) reports a comprehensive study on the characterisation, expression and evolution of {u03B1}- and {u03B2}-globin gene clusters in the platypus, using a combination of molecular and bioinformatics approaches. The most important findings from this work leading to the development of a new and simple model for globin gene evolution concerned the discovery of a {u03B2}-like globin gene within the a-globin cluster and genomic context analysis of {u03B1}- and {u03B2}-globin clusters across vertebrates. I showed that the amniote a-globin cluster is in fact the same as the a-{u03B2} cluster found in fish and amphibians, and both clusters share common flanking genes (C16orf35 and LUC7L). I proposed a transposition model in which a copy of {u03B2}-globin gene was inserted into a cluster of olfactory receptors (flanked by RRMl, CCKBR and ILK) in the ancestor of amniotes, thus originating the amniote {u03B2}-globin cluster. To elaborate this model further, my second paper (Chapter 3) reviews some events that could have led to this transposition, and their effects on the current fate of regulation. Information on the organization of globin genes in reptiles was required to test this transpositional model. I looked into the globin gene organization in the green anole using a bioinformatics approach and in the bearded dragon using a molecular approach. The results are reported in Chapter 4 and my third paper, which describe how fragmentary data from the green anole genome sequence assembly and mapping data from bearded dragon provided further evidence to support my proposed model for the evolution of the {u03B2}-globin gene cluster in amniotes. I also studied the evolution of regulatory regions of the platypus {u03B1}- and {u03B2}-globin clusters to address the question whether the translocation of the {u03B2}-globin locus resulted in a transposition of its regulatory region, or whether a new regulatory region evolved as a result of this translocation (reported in the fourth paper, Chapter 5). By using some novel techniques, I showed that the platypus a-globin has a major regulatory element that is conserved with other jawed vertebrates, whereas the regulatory regions of their {u03B2}-globin cluster do not show any conservation at the sequence level to those of birds and therian mammals. This suggested that the regulatory regions of amniote {u03B2}-globin genes evolved either more rapidly (more substitutions) or more extensively (e.g. more rearrangements) from a common ancestral regulatory region. Alternatively, these regulatory regions may have independent origins in different amniote lineages. In my final chapter, I discuss the overall implications of my findings on this area of research. I highlight the special value of studying non-model species mammals and reptiles, by which researchers are able to gain novel information about globin evolution and regulation.