# High Prevalence of Lesions of Systemic Hypertension in Bile-Extracted Asiatic Black Bears (Ursus thibetanus) and Associated Renal Disease

## TL;DR

This study finds that most bile-extracted Asiatic black bears have high rates of hypertension-related health issues and kidney disease.

## Contribution

The study identifies a strong link between systemic hypertension lesions and renal disease in bile-extracted bears.

## Key findings

- Over 75% of bears showed at least one lesion of systemic hypertension.
- Left ventricular hypertrophy and aortic dilation were the most common hypertension-related lesions.
- Systemic hypertension lesions were positively associated with kidney disease markers like serum creatinine.

## Abstract

Approximately 17,000 bears experience cumulative health and welfare harms in bile extraction facilities to supply traditional medicines despite the availability of proven alternatives. High prevalences of aortic dilation and renal disease were previously reported in bile-extracted bears, which are conditions both associated with systemic hypertension. We hypothesized that renal disease is positively correlated with lesions of systemic hypertension in bile-extracted bears. Archived medical records, imaging, and samples from formerly bile-extracted bears were analyzed. Hypertensive retinopathy, left ventricular hypertrophy, and aortic dilation were used as validated correlates of systemic hypertension. Our study demonstrated an unexpectedly high prevalence of systemic hypertension in this population and the most common lesions were left ventricular hypertrophy and aortic root dilation. Over 75% of bears exhibited at least one systemic hypertension lesion, and 62.8% had two or more. Lesions of systemic hypertension were positively associated with renal disease, particularly serum creatinine. Identification of additional markers of impaired renal function and systemic hypertension deserves greater investigation for earlier detection and enhanced long-term care. Understanding the etiologies contributing to systemic hypertension in this population is critical due to consequent comorbidities and increasing numbers of bile-extracted bears finding their way to sanctuary.

Approximately 17,000 bears undergo bile extraction in facilities across Asia for traditional medicines despite the availability of proven alternatives. Bears are confined to cages and bile harvested from the gallbladder via needle aspiration, implanted catheters, or transabdominal fistulas. Bile-extracted bears develop numerous detrimental conditions, including abnormal repetitive behaviors, emaciation, dental disease, cholecystitis, hernias, abscesses, and neoplasia. A high prevalence of aortic dilation, commonly seen with systemic hypertension, was reported in bile-extracted bears, and aortic aneurysm rupture/dissection was the third leading cause of death in a population of 600 formerly bile-extracted bears. A high incidence of renal disease, a common cause of systemic hypertension in other species, was also identified in this population. We hypothesized that renal disease was positively correlated with lesions of systemic hypertension in bile-extracted bears. Archived medical records, imaging, and samples from 180 formerly bile-extracted bears were analyzed. Hypertensive retinopathy, left ventricular hypertrophy, and aortic dilation were used as validated correlates of systemic hypertension. The majority (76.1%) of bears exhibited at least one systemic hypertension lesion, and 62.8% had two or more lesions. Left ventricular hypertrophy was most common, followed by aortic dilation/aneurysm. Lesions of systemic hypertension were positively correlated to renal disease parameters of serum creatinine and renal histopathology. Understanding the etiology of systemic hypertension in this population is critical due to consequent comorbidities and increasing numbers of bile-extracted bears finding their way to sanctuary.