Minimally-invasive monitoring of renal health in reptiles

目前，全世界被评估的爬行动物物种中有多达36%被认为濒临灭绝。最常被提及的导致爬行动物数量减少的因素是气候变化、栖息地破坏、野猫等入侵物种、污染、宠物贸易和传染病。《2019年全球生物多样性和生态系统服务评估》强调，需要确定更好的指标，以监测自由放养物种如何受到气候变化的影响。虽然许多研究正在评估气候变化对哺乳动物物种的影响，但对爬行动物的研究却很少。变温动物严重依赖于它们的环境：过高的温度或脱水会影响它们的新陈代谢、免疫力和肾功能。通常，慢性脱水和温度过高会导致爬行动物肾脏疾病和痛风。因此，爬行动物可能比哺乳动物更严重地受到全球变暖的影响。预计到2100年，全球气温将上升2至4.8摄氏度。某些爬行动物的分布变化已经被观察到。然而，这种应对策略并不总是可行的，例如生活在岛屿上的爬行动物，比如马达加斯加特有的变色龙，濒临灭绝。因此，评估爬行动物种群的肾脏健康对于评估何时有必要进行易位计划是很重要的。此外，在加拿大，成千上万的爬行动物被当作宠物饲养。北美是全球最大的伴侣爬行动物消费市场，自2002年以来，合法交易的动物数量增加了22%。爬行动物也被关在笼子里，作为先导项目，最终目标是将它们放归野外。在这种情况下，监测个别爬行动物的健康状况是很重要的。然而，迄今为止，在爬行动物中还没有发现准确可靠的肾脏疾病血液标志物。该计划的目的是鉴定敏感和特异性血液标志物，以非侵入性方式评估爬行动物的肾功能。我们的具体目标是：1)在爬行动物中建立新开发的可用于狗和人的肾脏生物标志物的参考区间；2)在爬行动物肾脏疾病的实验模型中评估这些生物标志物的敏感性和特异性；3)在加拿大自由放养的爬行动物种群中评估被认为对肾脏健康评估敏感和特异性的生物标志物。该研究项目将包括3名硕士生，2名由美国动物医学学院认可的3年住院医师项目的住院医师（3年研究生项目，在获得兽医博士学位后至少2年招收兽医），以及通过第5年课程学分实习学习研究的兽医本科生，这些学生将获得兽医博士学位。

Currently, up to 36% of evaluated reptile species are considered threatened with extinction worldwide. The most commonly cited factors for herpetofauna decline are climate change, habitat destruction, invasive species such as feral cats, pollution, pet trade and infectious diseases. The Global Assessment of Biodiversity and Ecosystem Service of 2019 has emphasized the need to define better indicators to monitor how free-ranging species are affected by climate change. While many studies are underway to evaluate the impact of climate change on mammalian species, fewer studies are conducted about reptiles. Ectotherm species rely heavily on their environment: excessive temperature or dehydration affect their metabolism, immunity and renal function. Typically, chronic dehydration and excessive temperature will cause renal disease and gout in reptiles. Thus, reptiles may be impacted by global warming more drastically than mammals. It is anticipated that global temperature should increase by 2 to 4.8°C by 2100. Distribution shifts of certain reptile species have already been observed. However, this coping strategy is not always possible, for instance for reptiles living on islands, such as endemic Madagascar chameleons threatened with extinction. Therefore, assessing the renal health of reptile populations would be important to evaluate when translocation programs are warranted. In addition, thousands of reptiles are kept as pets in Canada. North America is the biggest consumer market for companion reptiles worldwide, with a 22% increase in the number of animals legally exchanged since 2002. Reptiles are also kept in captivity in head-start programs with the ultimate goal to release them into the wild. In this context, it is important to monitor individual reptile health status. However, no accurate and reliable blood marker of renal disease have been identified to date in reptiles. The objective of this program is to identify sensitive and specific blood markers to assess renal function in reptiles in a non-invasive manner. Our specific objectives are: 1) to establish reference intervals in reptiles for newly developed renal biomarkers commercially available for dogs and humans, 2) to evaluate the sensitivity and specificity of these biomarkers in an experimental model of renal disease in reptiles, and 3) to evaluate biomarkers deemed sensitive and specific for renal health assessment in a free-ranging population of reptiles in Canada. This research program will involve 3 master students, 2 residents enrolled in a 3-year residency program accredited by the American College of Zoological Medicine (3-year post-graduate program enrolling veterinarians at least 2 years after obtention of their veterinary doctorate) and undergraduate veterinary students learning about research through a credited externship during the 5th year of the curriculum leading to the doctorate in veterinary medicine.