Captive Reptiles Research Articles

Preliminary Notes on the Use of the Predatory Soil Mite Stratiolaelaps scimitus (Acari: Laelapidae) as a Biological Control Agent for Acariasis in Lizards

Abstract While commonly employed by the agricultural and horticultural industries, biological control has rarely been utilized in herpetological husbandry to treat infectious or parasitic diseases. This case study describes the use of the predatory soil mite Stratiolaelaps scimitus to treat parasitic mite infestations in two adult inland bearded dragons (Pogona vitticeps). Stratiolaelaps scimitus applied directly to the existing terrarium substrate appeared to have eliminated all traces of parasitic mite infestation in both lizards within 5 days. These results, although preliminary, highlight the potential utility of predatory mites and other biological control agents in the husbandry and veterinary management of reptiles in captivity.

Choanal and cloacal aerobic bacterial flora in captive green iguanas: a comparative analysis

The aims of this study were to characterize the choanal and cloacal aerobic bacterial flora in healthy captive green iguanas and to compare it with the bacterial flora of the biofilm present in the water container of each terrarium. Samples were collected from the choana and the cloaca of 20 healthy captive adult green iguanas and from the biofilm of 15 water containers. The final identification of aerobic bacteria was performed by matrix-assisted laser desorption ionization time-of-flight mass spectrometry.Salmonellapositive samples were serotyped. The most common strains observed at each test location were from 1) choanae:Staphylococcusspp.,Enterobacter cloacaeandComamonas testosteroni; 2) cloacae:Citrobacterspp.,Salmonellaspp. andCorynebacteriumspp.; and 3) biofilms:Pseudomonasspp.,Salmonellaspp. andAcidovoraxspp. We showed that apart fromSalmonellaspp., the choanal and cloacal bacterial flora differed from the microorganisms present in the biofilm of the animal’s water container. These data revealed that healthy captive adult green iguanas harbored several aerobic bacterial strains that in immunosuppressed reptiles may act as opportunistic pathogens. Also, several of the aerobic bacteria identified in samples are potential zoonotic agents. Characterization of the normal background flora in captive reptiles and their environment can contribute to an understanding of the spread of bacterial contamination and the risk of potential zoonotic diseases for people in contact with these animals.

The incidence and antibiotic resistance of Salmonella species isolated from cloacae of captive veiled chameleons

Salmonellacan be present in the intestinal flora of captive reptiles without clinical disease or it can cause life threatening morbidity. The presence of certain species ofSalmonellain reptiles is consistent with them being the source of contamination in some cases of human disease. Thus,Salmonellapositive animals can be a potential public health concern even more when strains acquire resistance to antibiotics. The nature and extent ofSalmonellaharboured by different species of reptiles commonly kept in captivity are not known. The aims of this study were to analyse the incidence ofSalmonellaspecies in cloacae as an indicator of the intestinal flora in a cohort of healthy captive bred female veiled chameleons. A cloacal sample was taken from each of fifteen healthy captive bred, adult female veiled chameleons that were housed at a teaching and research clinic.Salmonellaisolates were confirmed by matrix-assisted laser desorption ionization time-of-flight mass spectrometry and positive cases were serotyped by slide agglutination test.Salmonellaorganisms were detected in 12 chameleons. Eighty percent of chameleons harboured 1 of 4 subspecies and serovars ofSalmonella. All strains belonged to the speciesenterica, predominantly subspeciesenterica(91.7 %) and were distributed among 4 different serovars:S.Ago (58.3 %),S.Blijdorp (16.7 %),S.Tennessee (16.7 %) andS.IV 45:g,z51:- (8.3 %). Antibiotic resistance to streptomycin was detected in one of 12Salmonellastrains:S.IV 45:g,z51:-. Our study extended the list ofSalmonellafound in healthy captive animals and included serovarsS.Tennessee andS.IV 45:g,z51:- that have been associated with morbidity in humans.

Assessment of the reproductive status of female veiled chameleons (Chamaeleo calyptratus) using hormonal, behavioural and physical traits.

Egg binding is a common reproductive disorder in captive female reptiles leading to premature loss of breeding potential, or in severe cases death. It can result from failure to ovulate (and reabsorb) follicles; follicular stasis, or failure to lay eggs; dystocia. Reproductive status of female veiled chameleons (Chamaeleo calyptratus) in a research colony was assessed using enzyme immunoassay (EIA) of fecal reproductive hormones (estradiol; E2, progesterone; P, and testosterone; T) and their metabolites, ultrasound imaging of the reproductive tract, and receptivity to conspecific males. Periods of follicular growth (vitellogenesis) corresponded with increasing levels of E2, and following ovulation, a distinct change in morphology from round (follicles) to oval (eggs) structures, which was accompanied by a surge in P (>20-fold above baseline). P levels remained elevated throughout the gravid phase until just prior to oviposition. Length/width ratios of follicles and eggs were statistically different, but distinguishing a follicle from an egg based on the ratio was unreliable due to a large overlap in values. In animals that failed to ovulate on their first cycle, follicles began to recede but were not fully reabsorbed and could be distinguished from a second batch of follicles based on their echogenicity. Female receptivity to conspecific males was not related to cycle stage (i.e., previtellogenesis, vitellogenesis, or gravid) or reproductive hormone levels. This study demonstrates the use of ultrasonography and reproductive hormone analysis to assess phase of the reproductive cycle (pre- or post-ovulatory), or confirm ongoing follicular stasis.

Vitamin D and Ultraviolet B Radiation Considerations for Exotic Pets

Vitamin D is an essential hormone that regulates many different functions in vertebrates and can have a protective effect against various disease conditions. Providing exotic pets appropriate access to vitamin D, through the diet, ultraviolet B (UVB) exposure, or a combination of both, is important for veterinarians and exotic pet owners to consider. Although it is commonly thought that most animals derive the vitamin D they need through their diet, there are a number of species that appear to benefit more from UVB exposure. In addition, there has been minimal study to investigate appropriate dietary levels of vitamin D for many of our exotic pets. Although the recommendation of providing UVB lighting has been primarily limited to captive reptiles, research with other species (e.g., birds and small mammals) suggests that these animals may also benefit from this type of lighting. However, the provision of UVB is not without its potential side effects. The purpose of this article is to review the important roles of vitamin D in animals, the different methods animals use to acquire this hormone, the potential clinical signs associated with hypovitaminosis or hypervitaminosis D, the role of artificial UVB lighting in the synthesis of vitamin D, and the potential side effects associated with UVB radiation.

How to Assess Stress in Reptiles

Stress, as an adaptive response of any animal to a stimulus that presents a threat to homeostasis, can occur in reptiles. Yet, many veterinarians fail to recognize the signs of stress in reptiles. In this article, evaluation of reptile stress has been discussed with a focus on the analysis of behavioral changes, neuroendocrine correlation, and biochemical and physiologic effects in reptiles. If stress can be assessed and treated properly in captive reptiles, their health and well-being can be optimized.

The Morality of the Reptile "Pet" Trade

Abstract The trade in, and private keeping of, reptiles as "pets" raises several ethical concerns regarding animal welfare (associated with handling, storage, transportation, intensive captive breeding, captivity stress, injury, disease, and high premature mortality); public health and safety (associated with zoonotic disease and animal-linked injuries); species conservation and environmental degradation (associated with wild capture); and ecological alteration (associated with invasive alien species). Also, many captive reptiles are fed other animals, raising broader ethical questions. Misperceptions about reptiles by proponents of their captivity mean that these animals are subject to conditions that would likely be considered unacceptable for dogs or cats.

Differential transcription of fathead minnow immune-related genes following infection with frog virus 3, an emerging pathogen of ectothermic vertebrates

Frog virus 3 (FV3) and other ranaviruses are responsible for die-offs involving wild, farmed, and captive amphibians, fish, and reptiles. To ascertain which elements of the immune system respond to infection, we explored transcriptional responses following infection of fathead minnow cells with either wild type (wt) FV3 or a knock out (KO) mutant targeting the 18kDa immediate early gene (18K). At 8h post infection we observed marked upregulation of multiple transcripts encoding proteins affecting innate and acquired immunity. Sequences expressed 4-fold or higher in wt-infected cells included transcripts encoding interferon (IFN), IFN regulatory factors (IRFs), IFN stimulated genes (ISGs) such as Mx and MHC class I, and interleukins IL-1β, IL-8, IL-17C and IL-12. Cells infected with the 18K KO mutant (∆18K) showed qualitative differences and lower levels of induction. Collectively, these results indicate that ranavirus infection induced expression of multiple cellular genes affecting both innate and acquired immunity.

Aspectos anátomo-radiográficos e tempo de trânsito gastrintestinal em jacaré tinga Caiman crocodilus crocodilus (Linnaeus, 1758) (Crocodylia, Alligatoridae)

In Brazil, there is increasing interest in the establishment of captive breeding programs for caiman. However, there is a paucity of in-depth studies on the proper care of these reptiles in captivity, particularly regarding optimal food type and frequency of feeding. The purpose of this study was to determine radiographic-anatomical aspects of, and gastrointestinal transit time of Caiman crocodilus crocodilus using contrast radiography. Ten caiman were used in the study, five males and five females, the animals were physically restrained for administration of a radiographic contrast medium, consisting of 10 ml/kg barium sulfate and mineral oil suspension (70%: 30% respectively), via the orogastric tube. Following contrast medium administration, radiographs were taken via dorsoventral projection first at five minutes, then at 6, 24, 30, 48, 54, 72, 80, 96, 104, 120, 130, 144 and 150 hours. This technique allows visualization of contrast medium passage through the GI tract, which enabled determination of gastrointestinal transit time in the spectacled caiman. The average time for contrast medium passage through the digestive tract of this species was 117 ± 29.6 h for females and 86.4 ± 21.5 h for males.

Multidrug-Resistant Pseudomonas aeruginosa Isolates From Captive Reptiles

Pseudomonas aeruginosa represents an opportunistic pathogen for animals and humans that is often associated with high disease morbidity and, at times, mortality. Captive reptiles have been shown to be reservoirs of P. aeruginosa strains that can be sources of exposure to humans that come in contact with these animals. In this study, the prevalence of P. aeruginosa among subclinical captive reptile species and the antimicrobial sensitivity of bacterial isolates were investigated. Sixty-five oral swabs were collected from captive reptiles belonging to 15 different species in which no overt signs of disease were evident. From this group of animals, 46 (70.8%) isolates were identified as P. aeruginosa. All of the P. aeruginosa strains were shown to have a wide range of antibiotic resistance. At present, there is a paucity of data regarding the prevalence of P. aeruginosa in various reptile species; therefore, continued scientific investigations are indicated to determine the significance of P. aeruginosa infection as it relates to captive reptile species.

Identification using microchips in exotic species

This article, the first in a series of exotic articles, discusses the methods of physically identifying exotic pets now kept commonly in captivity and presented to the clinician in practice. Identification allows association to an owner and allows completion of any paperwork such as CITES and import/export forms. The different identification methods will be described, from rings to microchips. Methods and location of application will be explained, along with any associated risks. A further three articles will cover species identification by visual methods and basic husbandry will be outlined, together with methods to aid in accurate sexing of captive reptiles, birds and small mammals.

Pathologic mineralization in captive reptiles.

Pathologic mineralization in reptiles is most commonly associated with hypervitaminosis D,due to overdosage by the owners. Other causes include secondary hiperparathyroidism, renal failure orother metabolic diseases. Over a period of 3 months, 4 reptiles were brought to the necropsy departmentby different owners. We necropsied a 6 year old male green iguana (Iguana iguana), a 7 year old femalered-eared slider (Trachemis scripta elegans), and two veiled chameleons (Chamaeleo calyptratus), an 8month old female and a 6 month old male respectivley. Although the cause of death varied among cases,all four reptiles had more or less severe lesions of pathologic tissue mineralization. These lesions weremost commonly found in arterial media in the form of medial calcification, but also we found tissuecalcifications in the myocardium, lungs and in the genital tract (ovaries). In all cases the arterial mediawas calcified, from incipient lesions consisting of calcified reticulin fibers within the media, to severelesions, that were seen macroscopically, in which the entire media was calcified, and decalcification wasneeded in order to process the tissue samples.

Metabolic bone disease in reptiles: Part 1

Metabolic bone disease is commonly seen in captive reptiles, especially Lizards and Chelonia. The reason for this lies with their mechanisms of Vitamin D and calcium metabolism. Many species do not appear to have the capability to absorb dietary Vitamin D. Instead they rely on the biosynthesis of endogenous vitamin D when in the presence of UV-B light and at a suitable temperature. Calcetriol (active Vitamin D) is required for absorption of dietary calcium. Therefore a lack of suitable UV-B provision, suitable temperature and suitable dietary calcium can all predispose to metabolic bone disease.

Isolation and identification of mycobacteria from captive reptiles

The occurrence of Mycobacterium species in clinically healthy pet reptiles was studied in Italy during the period 2004–2006. The feces samples of 223 animals were examined bacteriologically. Thirty-seven strains were isolated, in particular from 13/18 (72.2%) ophidians, 13/134 (9.7%) saurians and 11/71 (15.5%) chelonians. The isolates were classified, after HPLC analysis of bromophenacyl esters of cell wall mycolic acids, as Mycobacterium fortuitum (14 strains, 37.8%), Mycobacterium fortuitum-like (17, 45.9%), Mycobacterium peregrinum (4, 10.8%), and Mycobacterium chelonae (1, 2.7%). M. fortuitum was isolated from seven pythons, five saurians and two turtles; M. fortuitum-like from six saurians, six pythons and five turtles; M. peregrinum from four turtles; M. chelonae from one lizard. One isolate from an Iguana iguana could not be identified by HPLC analysis showing a previously unreported profile. Comparative 16S rDNA sequencing showed a low similarity with Mycobacterium triviale (97.2%) and Mycobacterium confluentis (97.1%). On the basis of such data the unidentified bacterium turned out to belong to a not yet described Mycobacterium species.

Dispatches

Dispatches

Variation in Growth and Potentially Associated Health Status in Hermann's and Spur‐Thighed Tortoise (Testudo hermanni and Testudo graeca)

Captive reptiles often show higher growth rates than in the wild, possibly due to higher feeding intensity. Although health problems are usually linked to inappropriate diets, fast growth itself, such as triggered by appropriate diets fed in high amounts, has traditionally also been considered unfavorable for tortoises. We document growth rates (based on age and mass) from private Testudo hermanni and T. graeca breeders, which are generally higher than those reported for free-ranging specimens, but show enormous variation. Tortoise patients presented to an exotics clinic also covered the whole growth rate spectrum. To test whether fast growth was associated with diseases, the age-body mass relationship of these patients was tested, in a retrospective evaluation, for additional influence factors, such as dietary history and occurrence of certain diet and growth-related diseases. No indication was found that animals particularly heavy for their age were more prone to diet/growth-related disorders. In general, tortoises fed diets with meat/grain were heavier for their age than tortoises fed more appropriate diets; dietary history was not related to a particular disease. The results suggest the age-body mass relationship may not be suitable for testing effects of fast growth; an age-body length relationship would be more appropriate. Animals presented for a diet/growth-related disorder were younger than animals presented for other reasons; there was a significant negative correlation between the severity of pyramiding and age, suggesting that growth-related disorders may well limit the life expectancy of tortoises. Controlled clinical studies are required to fully test this hypothesis.

Zoonotic Risks from Amphibians and Reptiles

Captive amphibians and reptiles are well-documented sources of human salmonellosis through direct contact with contaminated feces or fomites. However, the relative significance of wild cold-blooded vertebrates as hosts/reservoirs of zoonotic enteric pathogens in their natural habitat is not known. Wild amphibian and reptile populations are present in the leafy green produce production environment in the central California coast, and there are reports from growers that frogs and other species sometimes intrude into produce fields. These intrusions may result in destruction of the crop and economic losses, due to food safety and quality concerns. Environmental groups have also noted potential conflicts between conservation efforts and food safety practices that result in removal or damage to aquatic habitat (e.g., farm ponds, adjacent wetland areas). To address these concerns, we conducted a survey of foodborne pathogen prevalence in common amphibian and reptile populations during the 2011 produce growing season in the central California coast. Preliminary results indicate that Salmonella prevalence was higher among wild-caught reptile (33%) compared with amphibian (4%) taxa. In contrast, all samples were negative for E. coli O157. Wildlife damage management in fresh produce production fields is challenging, due to the diversity of potential hosts/reservoirs of foodborne pathogens and a limited number of mitigation strategies. Professionals working in vertebrate pest control could play an important role in assisting fresh produce growers with implementation of co-management approaches that promote public health and conservation goals in the central coast agricultural landscape.

PRESENÇA DE CORPOS ESTRANHOS NO APARELHO DIGESTÓRIO DE JABUTIS PIRANGA (Chelonoidis carbonaria): RELATO DE CASO

The ingestion of foreign bodies by captive reptiles is related to the maintenance of these animals in unsuitable places. This report refers to the description of ingestion cases of weird foreign bodies by three jabuti piranga (Chelonoidis carbonaria) from keepers in Sergipe, Brazil. The animals were sent for medical care with a history of apathy, prostration, loss of appetite and constipation. After anamnesis and clinical evaluation the specimens were submitted to simple ventrodorsal radiographs that confirmed the presence of radiopaque material in the digestive tract. Therapeutic procedures were different and one of the animals died due to the seriousness of his condition. From that report we concluded that the occurrence of ingestion of foreign bodies may occur when treatment is inadequate. Keywords: Reptiles, digestive tube, foreign body.

Prevalence of Salmonella spp., and serovars isolated from captive exotic reptiles in New Zealand

AIM: To investigate the prevalence of Salmonella spp. in captive exotic reptile species in New Zealand, and identify the serovars isolated from this population. METHODS: Cloacal swabs were obtained from 378 captive exotic reptiles, representing 24 species, residing in 25 collections throughout New Zealand between 2008 and 2009. Samples were cultured for Salmonella spp., and suspected colonies were serotyped by the Institute of Environmental Science and Research (ESR). RESULTS: Forty-three of the 378 (11.4%) reptiles sampled tested positive for Salmonella spp., with 95% CI for the estimated true prevalence being 12–25% in exotic reptiles in this study population. Lizards tested positive for Salmonella spp. more often than chelonians. Agamid lizards tested positive more often than any other family group, with 95% CI for the estimated true prevalence being 56–100%.. Six Salmonella serovars from subspecies I and two from subspecies II were isolated. The serovar most commonly isolated was S. Onderstepoort (30.2%), followed by S. Thompson (20.9%), S. Potsdam (14%), S. Wangata (14%), S. Infantis (11.6%) and S. Eastbourne (2.3%). All of the subspecies I serovars have been previously reported in both reptiles and humans in New Zealand, and include serovars previously associated with disease in humans. CONCLUSIONS AND CLINICAL RELEVANCE: This study showed that Salmonella spp. were commonly carried by exotic reptiles in the study population in New Zealand. Several serovars of Salmonella spp. with known pathogenicity to humans were isolated, including S. Infantis, which is one of the most common serovars isolated from both humans and non-human sources in New Zealand. The limitations of this study included the bias engendered by the need for voluntary involvement in the study, and the non-random sampling design. Based on the serovars identified in this and previous studies, it is recommended native and exotic reptiles be segregated within collections, especially when native reptiles may be used for biodiversity restoration. Veterinarians and reptile keepers are advised to follow hygiene protocols developed to minimise reptile-associated salmonellosis.

PREVALENCE OF SALMONELLA IN AUSTRALIAN REPTILES

From January 2007 until June 2008, 504 reptiles of four families and 57 species were examined for Salmonella by using cloacal or intestinal swabs. Salmonella was identified in 139 (28%) of the 504 animals tested. Of the 504 reptiles examined, 210 were captive and 294 were wild. Ninety-eight (47%) of the captive reptiles were shedding Salmonella at the time of sampling. In contrast, only 41 (14%) of the wild reptiles were shedding Salmonella. The higher prevalence of Salmonella in captive reptiles was statistically significant (P<0.0001). No Salmonella was found in 60 wild, freshwater chelonians or 48 wild southern water skinks (Eulamprus heatwolei). Our results suggest that some species of wild reptiles in Australia are not natural carriers of Salmonella and that diet and captivity may influence Salmonella excretion in other species.