Clinical Reptile Behavior

EVALUATION OF MORTALITY CAUSES AND PREVALENCE OF RENAL LESIONS IN ZOO-HOUSED CHAMELEONS: 2011-2022

Of the 202 species of Chamaeleonidae, 38.6% are globally threatened. Currently, nearly a thousand individual chameleons from 36 different species are kept in zoological institutions worldwide. The objectives of this study were to assess the main mortality causes of chameleons in zoological institutions, the prevalence of renal lesions at necropsy, and the environmental factors associated with renal lesions. An online survey was sent to 245 zoological institutions worldwide to collect information about species and sex distribution, necropsy results, and husbandry parameters. Necropsy reports of the last 10 yr were requested from participating institutions (n = 65) when available. Mortality causes were classified into three categories (open diagnosis, infectious, and noninfectious), and noninfectious causes were further subdivided into seven categories (renal, reproductive, myoarthroskeletal, digestive, ophthalmologic, denutrition/multisystemic, and neoplastic). The prevalence of renal lesions was recorded. Multiple linear regression models were used with the prevalence of renal diseases as the dependent variable, and exhibit minimum and maximum hygrometry; exhibit highest and coolest temperature; as well as minimum, mean, and maximum hygrometry of the geographical area as independent variables, combining all chameleon species with similar environmental requirements. Results were obtained for 14 species (n = 412 individuals). The main mortality causes were infectious (46.8%), noninfectious renal (11.4%), and noninfectious reproductive (10.7%) diseases, with all cases of fatal reproductive diseases reported in females. Of the individuals that underwent renal histopathology, 41.7% displayed renal lesions. There was a tendency towards higher renal lesion prevalence in zoos located in areas with lower mean hygrometry (P = 0.05). Further research studies about infectious, renal, and reproductive diseases of Chamaeleonidae are warranted.

Reaction to Novel Objects and Fecal Glucocorticoid Metabolite Levels in Two Species of Nocturnal Geckos

Many reptiles are maintained in captivity and heavily traded, although welfare measures for many species are not well established and are under-researched compared to other animals. In this study, we focused on two of these species: crested geckos (Correlophus ciliatus) and leopard geckos (Eublepharis macularius). To better interpret their behavior in captivity, the individual reaction to novel objects and the fecal glucocorticoid metabolite levels were measured in an attempt to identify the potential correlation between them. Also, we explored if some characteristic of the objects (e.g., color, shape, or smell) resulted in being more attractive to some species and/or individuals. Equivalent responses to different objects were not obtained for all the geckos, the behavioral response being highly individual and context-dependent, although modulated by the species. Individuals which manipulated earlier and interacted longer with novel objects showed lower basal fecal corticosterone metabolite (FCM) levels. Differences according to the species suggested that crested geckos have significantly greater and more variable FCM levels than leopard geckos. Our results can help to understand the reaction of geckos to novelty and have the potential to serve in their welfare assessment, although more studies are needed to proper establish welfare protocols.

Pain Recognition in Reptiles

Advances in reptile cognitive research would help to (1) better qualify behavioral responses to pain experiences, (2) monitor welfare impacts, and (3) model analgesic studies with ecologically relevant insight to better qualify interventional responses. The focus of future analgesic studies in reptiles require the continued elucidation of the opiate systems and the given variations across taxa in efficacy in nociceptive tests.

Identification of Animal-Based Welfare Indicators in Captive Reptiles: A Delphi Consultation Survey

There is an increasing focus on evidence-based welfare assessment by animal care staff in zoos, along with a strong interest in animal welfare by the zoo-visiting public, to the extent that this can influence their choice of institutions to visit. Regulatory oversight of animal welfare standards continues to strengthen across many jurisdictions. Zoos are increasingly formalizing their practices with the development and refinement of evidence-based welfare assessment tools. There has been a drive for welfare assessment tools to comprise both resource-based and animal-based measures. However, animal-based indicators are not always well characterized, in terms of their nature and whether they infer a positive or negative affective state. This is especially so for reptiles, which are often considered behaviorally inexpressive and are under-researched. In this study, a Delphi consultation approach was used to gather expert opinion on the suitability of potential animal-based indicators of welfare for inclusion in a welfare assessment tool across four families of reptiles: Agamidae, Chelidae, Pythonidae, and Testudinidae. Two rounds of online surveys were conducted eliciting responses from a global group of professionals who work with reptiles. In the first survey, respondents were provided with an author-derived list of potential animal-based indicators for consideration of their validity and practicality as welfare indicators. The indicators were refined for the second survey including only those indicators that were considered valid or practical on the first survey (≥4 on a 5-point Likert scale), and that achieved ≥70% consensus amongst experts. In the second survey, respondents were asked to re-evaluate the reliability and practicality of the indicators and to rank them on these facets. Eight to ten assessment indicators for each family of reptiles were identified from Survey 2. These indicators were often health related, for example, presence of oculo-nasal discharge or wounds. However, some true behavioral indicators were identified, such as showing species-specific interest and alertness. These indicators should now be incorporated into taxon-tailored welfare assessment tools for trial and validation in captive reptile populations. This study provides a next step towards developing reptile-specific animal welfare assessment tools for these often-overlooked animals.