Fahrenholz ICDennis MMMorandi FDittmer KESheldon JDGottdenker NTinelli A2024-08-092024-08-092024-07-17Fahrenholz IC, Dennis MM, Morandi F, Dittmer KE, Sheldon JD. (2024). Debilitating Musculoskeletal Disease in Two Free-Ranging Juvenile American Black Bears (Ursus americanus).. Animals (Basel). 14. 14. (pp. 2088-).2076-2615https://mro.massey.ac.nz/handle/10179/71252Severe 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.(c) 2024 The Author/sCC BY 4.0https://creativecommons.org/licenses/by/4.0/American black bearUrsus americanuschondrodysplasiaepiphyseal dysplasiajoint laxityosteoporosisvitamin DJournal article10.3390/ani141420882076-2615journal-article2088-https://www.ncbi.nlm.nih.gov/pubmed/390615502088ani14142088