School of Animal and Veterinary Sciences, Roseworthy Campus, University of Adelaide, Roseworthy, South Australia, Australia.
Vet Pathol. 2013 Mar;50(2):299-307. doi: 10.1177/0300985812456215. Epub 2012 Aug 1.
The wild and captive koala population of the Mt Lofty Ranges in South Australia has a high level of renal dysfunction in which crystals consistent with calcium oxalate have been observed in the kidneys. This study aimed to describe the pathological features of the renal disease in this population, confirm the composition of renal crystals as calcium oxalate, and determine whether any age or sex predispositions exist for this disease. A total of 51 koalas (28 wild rescues, 23 captive) were examined at necropsy, of which 28 (55%) were found to have gross and/or histological evidence of oxalate nephrosis. Histopathological features included intratubular and interstitial inflammation, tubule dilation, glomerular atrophy, tubule loss, and cortical fibrosis. Calcium oxalate crystals were demonstrated using a combination of polarization microscopy, alizarin red S staining, infrared spectroscopy, and energy-dispersive X-ray analysis with scanning electron microscopy. Uric acid and phosphate deposits were also shown to be present but were associated with minimal histopathological changes. No significant differences were found between the numbers of affected captive and wild rescued koalas; also, there were no sex or age predispositions identified, but it was found that oxalate nephrosis may affect koalas <2 years of age. The findings of this study suggest that oxalate nephrosis is a leading disease in this koala population. Possible causes of this disease are currently under investigation.
南澳大利亚洛夫蒂山脉的野生和圈养树袋熊种群中，肾脏功能障碍程度较高，肾脏中观察到与草酸钙一致的晶体。本研究旨在描述该人群肾脏疾病的病理特征，确认肾脏晶体的成分是否为草酸钙，并确定该疾病是否存在任何年龄或性别倾向。在尸检中检查了总共 51 只考拉（28 只野生救援，23 只圈养），其中 28 只（55%）被发现有草酸肾病的大体和/或组织学证据。组织病理学特征包括肾小管和间质炎症、小管扩张、肾小球萎缩、小管丢失和皮质纤维化。使用偏振显微镜、茜素红 S 染色、红外光谱和带有扫描电子显微镜的能量色散 X 射线分析相结合的方法证明了草酸钙晶体的存在。还显示尿酸和磷酸盐沉积物的存在，但与最小的组织病理学变化相关。受影响的圈养和野生救援考拉的数量之间没有发现显著差异；也没有发现性别或年龄倾向，但发现草酸肾病可能影响<2 岁的考拉。本研究的结果表明，草酸肾病是该考拉种群中的主要疾病。目前正在调查这种疾病的可能原因。
