A retrospective study on the prevalence of main clinical findings in brown bears (Ursus arctos) rescued from substandard husbandry conditions

**Background:** Captive brown bears (Ursus arctos) are often kept in substandard conditions (e.g., substandard zoos, circuses, private keeping, baiting stations, dancing bears) that fail to meet their physical, nutritional, and behavioral needs. Such conditions can lead to a range of health issues, but comprehensive data on the prevalence of clinical findings across body systems in rescued bears are limited. This study aimed to provide an overview of pathologies and clinical abnormalities reported in veterinary records of brown bears rescued by FOUR PAWS International and housed in species-appropriate sanctuaries, and to examine the prevalence of these findings according to pre-rescue origin.

**Methods:** Data were extracted from 302 veterinary reports of medical examinations (278 in vivo, 24 post-mortem) performed between 2006 and 2021 on 114 brown bears housed in six FOUR PAWS sanctuaries in Europe. Bears were rescued from 1998 to 2021, with ages at rescue ranging from a few months to 30 years (median 13 years). Pre-rescue origins included substandard zoos (n=32), dancing bears (n=27), restaurant bears (n=23), private keeping (n=16), circus bears (n=10), and bear-baiting (n=6). Clinical findings were extracted from reports and categorized by body system and neoplasia. Prevalence was calculated as a percentage of total findings (n=1,003) and also relative to the number of reports per origin.

**Key Results:** The most frequently affected body systems were: oral cavity (56.0% of all findings), abdominal cavity and digestive system (7.9%), integumentary system (7.9%), ocular system (7.7%), and musculoskeletal apparatus (7.6%). Neoplasia accounted for 2.8% of findings. Within the oral cavity, the most common subcategory was teeth fractured, destroyed, worn, or with attrition (31.9% of oral findings), followed by open roots (24.6%). Dancing bears showed the highest prevalence of missing teeth (44.4% of reports), cavities (18.9%), open roots (58.9%), and apical/periapical lesions (27.8%). Ocular findings were most prevalent in dancing bears, with lens luxation or cataract in 21.1% of reports. Musculoskeletal findings, particularly coxofemoral osteoarthritis (22.4% of musculoskeletal findings) and spine arthrosis/spondylosis (21.1%), were most common in subzoo bears. Malignant neoplasia was reported in 75% of neoplasia cases, with circus, subzoo, and dancing bears showing the highest prevalence.

**Clinical Implications:** The high prevalence of oral, ocular, and musculoskeletal pathologies in rescued brown bears underscores the long-term health consequences of substandard husbandry. The variation in findings by pre-rescue origin suggests that specific preventive veterinary and husbandry plans should be tailored to each origin. For example, dancing bears may benefit from enhanced ophthalmic monitoring, while subzoo bears require attention to joint health. Improved record-keeping and standardized diagnostic protocols are essential for early detection and management. These findings contribute to evidence-based welfare improvements for captive brown bears and highlight the need for further research on the role of specific husbandry factors in disease development.