PDF(Pubmed)
Abstract：
Severe musculoskeletal disease characterized by marked joint laxity was the cause of euthanasia in two wild juvenile American black bears (Ursus americanus) admitted to a rehabilitation facility in eastern Tennessee in 2023. Previously, almost all reported musculoskeletal diseases in this population were of traumatic etiology, even in malnourished yearlings. Case 1 was an orphaned 11-month-old male cub exhibiting disproportionate dwarfism, progressive immobility, and joint laxity. Necropsy findings suggested either chondrodysplasia or rickets, and imaging findings supported a skeletal dysplasia. Case 2 was a 14-month-old emaciated male yearling exhibiting joint laxity and immobility. Necropsy findings showed osteoporosis and serous atrophy of fat, and imaging findings were inconsistent with a skeletal dysplasia. Both cases were clinically inconsistent with rickets based on normal calcium, phosphorous, and parathyroid hormone concentrations; however, Case 1 had hypovitaminosis D (9 nmol/L) compared to healthy juvenile black bears. We hypothesize that Case 1 had a genetic chondrodysplasia while the osteoporosis of Case 2 was due to chronic malnutrition. The goal of this case report is to inform wildlife agencies and facilities to monitor for similar, non-trauma-related debilitating musculoskeletal disease in free-ranging bears and evaluate cases that allow us to further understand the disease processes involved.
摘要：
以关节松弛为特征的严重肌肉骨骼疾病是2023年在田纳西州东部接受康复治疗的两只野生幼年美洲黑熊（Ursusamericanus）安乐死的原因。以前,该人群中几乎所有报道的肌肉骨骼疾病都是创伤性病因，即使是营养不良的一岁。病例1是一只11个月大的孤儿雄性幼崽，表现出不成比例的侏儒症，渐进不动，和关节松弛。尸检结果显示软骨发育不良或病，影像学检查结果支持骨骼发育不良。病例2是一个14个月大的瘦弱的男性一岁一岁，表现出关节松弛和不活动。尸检结果显示骨质疏松症和脂肪浆液性萎缩，影像学检查结果与骨骼发育不良不一致.根据正常的钙，这两个病例在临床上都不一致，磷,和甲状旁腺激素浓度；然而，与健康的幼年黑熊相比，病例1具有维生素D缺乏症（9nmol/L）。我们假设病例1患有遗传性软骨发育不良，而病例2的骨质疏松症是由于慢性营养不良。本病例报告的目的是通知野生动物机构和设施监测类似情况，自由放养熊中非创伤相关的衰弱性肌肉骨骼疾病，并评估病例，使我们能够进一步了解所涉及的疾病过程。
