Abstract
Animals Asia has rescued 277 Asiatic black bears (Ursus thibetanus) from bile farms in China, where bears experience serious welfare issues.6 Aortic aneurysms in animals, while not commonly reported, can be associated with heredity, parasites, nutrition, and hypertension.2,4,5,7 Aortic aneurysm was diagnosed in nine bears at the China Bear Rescue Centre (CBRC) (Longqiao, Chengdu, China) through radiographs, computed tomography, and necropsies. Eight of the nine bears died, with dissecting aortic aneurysm as the cause of death in four. One of the deceased bears had hemopericardium without evidence of aortic dissection. Necropsies confirmed aortic aneurysm in three bears euthanized due to other conditions: spinal paresis, a nasal tumor, and unresponsive head-pressing. Clinically, one of the deceased bears coughed, likely related to severe aortic dilation. The surviving bear remains asymptomatic. Preliminary histopathology of necropsied bears revealed no primary aortic abnormalities. High prevalence of retinal and renal pathology in farmed bears may be attributed to hypertension and suggests an association with aortic aneurysm in this population. Seven (4.6%) of 152 bears at CBRC receive oral enalapril (0.5 mg/kg BID, Enalapril, Yabao Pharmaceutical Group, Shanxi, China) and amlodipine (0.05–0.1 mg/kg SID/BID, Norvasc, Beijing Yimin Pharmaceutical, Beijing, China) as treatment for suspect hypertensive retinopathy that was identified by fundic examination. In humans, aortic aneurysms and associated hypertension are well documented.1,3 To the authors’ knowledge, this is the first report of aortic aneurysms in ursids. Understanding the etiology of aortic aneurysms in this population is of importance, considering the severe health implications when rehabilitating farmed bears.
Literature Cited
1. Bickerstaff, L.K., P.C. Pairolero, L.H. Hollier, L.J. Melton, H.J. Van Peenen, K.J. Cherry, J.W. Joyce, J.T. Lie. Thoracic aortic aneurysms: a population-based study. Surgery. 1982;92:1103–1108.
2. Chetboul, V., D. Tessier, N. Borenstein, F. Delisle, L. Zilberstein, G. Payen, E. Leglaive. B. Franc, G. Derumeaux, J.L. Pouchelon. Familial aortic aneurysm in Leonberg dogs. J Am Vet Med Assoc. 2003;22:1159–1162.
3. Coady, M.A., J.A. Rizzo, L.J. Goldstein, J.A. Elefteriades. Natural history, pathogenesis, and etiology of thoracic aortic aneurysms and dissections. Cardiology Clinics. 1999;17:615–635.
4. Gershenson, R.T., R. Melidone, J. Sutherland-Smith, C.L. Rogers. Abdominal aortic aneurysm associated with systemic fungal infection in a German Shepherd dog. J Am Anim Hosp Assoc. 2011;47:45–49.
5. Kirberger, R.M., N. Stander, N. Cassel, P. Pazzi, V. Mukorera, J. Christie, A. Carstens, E. Dvir. Computed tomographic and radiographic characteristics of aortic lesions in 42 dogs with spirocercosis. Vet Radiol Ultrasound. 2013;54:212–222.
6. Loeffler, I.K., J. Robinson, G. Cochrane. Compromised health and welfare of bears farmed for bile in China. Anim Welfare. 2009;18:225–235.
7. Overview of thrombosis, embolism and aneurysm. In: The Merck Veterinary Manual. Available at: www.merckmanuals.com/vet/circulatory_system/thrombosis_embolism_and_aneurysm/overview_of_thrombosis_embolism_and_aneurysm.html. Accessed March 19, 2013. (VIN editor: link could not be accessed on 12-11-20; a 2020 updated link is www.merckvetmanual.com/circulatory-system/thrombosis,-embolism,-and-aneurysm/thrombosis,-embolism,-and-aneurysm-in-animals)