School of Veterinary Science, The University of Queensland, Building, 8114, Gatton, Queensland, Australia.
California Animal Health and Food Safety Laboratory, UC Davis, 105 W Central Ave, San Bernardino, CA, 92408, USA.
Sci Rep. 2019 Nov 25;9(1):17494. doi: 10.1038/s41598-019-53970-0.
Koalas are an iconic Australian marsupial undergoing precipitous population reduction in South-East Queensland from complex interacting threats. To investigate the causes of death and the interaction of comorbidities with demography in South-East Queensland koalas, a large scale, high-throughput prospective necropsy survey was conducted spanning 2013-2016. During this period, 519 necropsies were conducted in 155 young/subadult koalas, 235 mature, 119 old koalas and 10 of unknown age. Similar numbers of males and females were assessed. Trauma and infectious disease at were the most common single diagnoses. However, comorbidity was frequent, including multicentric infection or infectious disease in combination with trauma or senescence. Female koalas had proportionally more reproductive chlamydiosis compared to males in which the ocular and urinary systems were more commonly affected. Comorbidity and disease were strongly associated with poor body condition, and trauma was associated with good body condition. Animals affected by motor vehicle trauma were often in better body condition than those affected by animal attack, tree fall or other causes of trauma. This study identified a higher frequency of infections and comorbidity then previously reported, confirming the complex nature of interacting threats to the koala population.
考拉是澳大利亚有袋类动物的标志性物种，但在昆士兰东南部，由于多种相互作用的威胁，考拉数量正在急剧减少。为了研究昆士兰东南部考拉死亡的原因，以及合并症与种群动态之间的相互作用，我们开展了一项大规模、高通量的前瞻性尸检调查，时间跨度为 2013 年至 2016 年。在此期间，对 155 只幼体/亚成体考拉、235 只成年考拉、119 只老年考拉和 10 只未知年龄的考拉进行了 519 次尸检。评估的雄性和雌性考拉数量相似。创伤和传染病是最常见的单一诊断。然而，合并症很常见，包括多中心感染或传染病合并创伤或衰老。与雄性考拉相比，雌性考拉的生殖衣原体感染比例更高，其中眼部和泌尿系统更常受到影响。合并症和疾病与较差的身体状况密切相关，而创伤与较好的身体状况相关。受机动车创伤影响的动物的身体状况通常优于受动物袭击、树木倒下或其他创伤原因影响的动物。本研究发现感染和合并症的频率高于之前的报告，证实了影响考拉种群的多种相互作用威胁的复杂性。
