A multi-scale analysis of modularity and ontogenetic changes in morphology and locomotor biomechanics in the domestic dog

该项目有两个总体目标：(1)分析不同犬种生长过程中骨骼的解剖和运动是如何变化的，以及这些生长轨迹如何与肌肉骨骼问题的发展联系起来；(2)利用这一新的认识，告知与品种标准相关的狗的健康问题，并帮助开发新的福利技术。家犬的体型差异很大，可能比任何四条腿的动物都要大。因此，狗代表了一种独特的模型动物，用于研究单一物种的变异极限，以及形状的变化如何与日常功能（如运动）相互作用。然而，与大多数动物的形态是通过数百万年的自然选择进化而来的不同，家养狗的体型多样性受到人类强烈而直接的影响。自维多利亚时代以来，狗一直是越来越严格的选择性育种的对象，目的是改变它们的功能解剖结构，以达到特定的目的，比如工作任务、敏捷性或仅仅是“理想的”视觉品质。关于某些狗的品种标准（体型）对福利的影响，有重大的科学和社会关注。某些疾病的明显的品种特异性患病率强烈地表明，我们的选择性育种所偏爱的许多身体特征可能通过产生对疾病或损伤的固有倾向而对肌肉骨骼功能产生有害影响。不幸的是，目前缺乏了解不同品种形态和功能力学（如运动运动）之间关系所需的科学数据。这种不了解严重限制了科学家、兽医和负责全球犬类福利政策的人解决与品种标准有关的健康问题的能力。确定犬种的形态和功能变异，以及这种变异如何使某些犬种易患肌肉骨骼问题，将提供多种长期福利。这些好处包括为修改育种标准和政策提供客观的科学依据，以及改进兽医治疗的设计，如物理治疗、矫形植入物和早期诊断工具。在这个项目中，我们将整合解剖学和运动方面的数据，以解决一系列假设，这些假设旨在测试品种标准是否以及如何对狗的肌肉骨骼系统提出不同的，有时是负面的机械要求。我们将比较不同犬种从幼年到成年的形态变化。比较将在一系列尺度上进行，从整个动物的身体比例测量到肢体骨骼的形状及其关节表面，它们必须承受运动中产生的负荷。我们将比较犬种的运动模式如何随着它们的成长而变化，使用一系列步态分析方法，包括双平面x射线摄像，这将使我们能够以无与伦比的精度测量腿骨的精细3D运动。然后，解剖学和运动数据将输入生物力学计算机模型，该模型提供肌肉和关节力的信息，以测试在肌肉骨骼健康问题高发的品种中是否存在机械不利条件。我们将通过与三个项目伙伴的直接合作，从这项科学中获得直接的福利影响。英国养犬俱乐部积极参与我们的项目，最大限度地发挥其影响未来育种政策和向下游品种社会传播科学的潜力。与两家工业合作伙伴的合作将看到新的狗福利技术的开发和验证，特别是一种新的骨科植入物和一种自动人工智能工具，可以根据主人的手机视频检测狗的早期行动问题。

This project has two over-arching goals: (1) to analyse how anatomy and movement of the skeleton change during growth in different canine breeds and how these growth trajectories might be linked with the development of musculoskeletal problems; and (2) to use this new understanding to inform health issues in dogs related to breed standards and aid development of new welfare technologies.The domestic dog varies remarkably in body shape, perhaps more than any four-legged species. As such, the dog represents a unique model animal for investigating the limits of variation within a single species and how variations in shape interact with everyday functions, such as movement. However, unlike most animals whose forms evolved through natural selection over millions of years, the diversity in body shape seen in domestic dogs has been strongly and directly influenced by humans. Since Victorian times, dogs have been the subject of increasingly intense selective breeding with the goal of altering their functional anatomy for specific purposes, such as working tasks, agility or simply 'desirable' visual qualities.There are major scientific and societal concerns about the welfare implications surrounding the breed standards (body shape) of certain dogs. The clear breed-specific prevalence for certain disorders strongly suggests that many of the physical traits favoured by our selective breeding may have a harmful effect on musculoskeletal function by creating an inherent predisposition to disease or injury. Unfortunately, the scientific data needed to understand the relationships between different breed morphologies and functional mechanics, such as locomotor movement, is currently lacking. This poor understanding has severely limited the ability of scientists, veterinarians and those responsible for canine welfare policy world-wide to address the health issues surrounding breed standards. Determining the morphological and functional variation in canine breeds, and how this variation may predispose certain breeds to musculoskeletal problems would provide multiple long-term welfare benefits. These benefits include an objective scientific basis for modifying breeding standards and policy, and improvements to the design of veterinary treatments, such as physiotherapy, orthopaedic implants and early diagnosis tools.In this project, we will integrate data on anatomy and movement to address a series of hypotheses designed to test if and how breed standards place disparate, and sometimes negative, mechanical demands on the musculoskeletal system of dogs. We will compare how the morphology of different canine breeds change as they grow from juveniles to adults. Comparisons will be made at a range of scales from whole-animal measures of body proportions down to the shapes of limb bones and their joint surfaces, which must bear the loads generated in locomotion. We will compare how the movement patterns of canine breeds change as they grow, using a range of gait analysis approaches, including biplanar x-ray videography, which will allow us to measure fine-scale 3D motion of leg bones with unparalleled accuracy. Anatomical and movement data will then feed into biomechanical computer models that provide information on muscle and joint forces to test if mechanically unfavourable conditions exist in breeds that show a high prevalence for musculoskeletal health issues. We will deliver direct welfare impact from this science through direct collaboration with three project partners. Active involvement of the UK Kennel Club in our project maximises its potential to influence future breeding policies and dissemination of science downstream into breed societies. Partnership with two industrial collaborators will see the development and validation of new canine welfare technologies, specifically a new orthopaedic implant and an automated artificial intelligence tool to detect early mobility issues in dogs based on owner mobile phone videos.