eng Rovedar Journal of Lab Animal Research 2980-9703 2026-02-14 5 1 1 14 10.58803/jlar.v5i1.88 98 Natalie Steiner 0 https://orcid.org/0000-0002-5057-1173 Tina Brezzina 1 https://orcid.org/0009-0001-4177-8025 Felix Felmy 2 https://orcid.org/0000-0002-0957-4241 Frederik Kiene 2 https://orcid.org/0000-0003-2517-8553 Yara Silberstein 2 https://orcid.org/0009-0006-3694-0557 Malgorzata Ciurkiewicz 3 https://orcid.org/0000-0001-6277-7366 Andreas Beineke 3 https://orcid.org/0000-0003-2187-3436 Jan Hinrich Bräsen 4 https://orcid.org/0000-0002-2863-3067 Reinhold Paul Linke 5 https://orcid.org/0009-0001-1067-5242 Claudia Busse 6 https://orcid.org/0009-0008-4070-7891 Michael Pees 7 https://orcid.org/0000-0002-7244-9697 Ute Radspiel 2 https://orcid.org/0000-0002-0814-2404 Maximilian Reuschel 7 https://orcid.org/0000-0001-8083-677X Department of Small Mammal, Reptile and Avian Medicine and Surgery, University of Veterinary Medicine Hannover, Foundation, Hannover, Germany. Institute for Terrestrial and Aquatic Wildlife Research (ITAW), University of Veterinary Medicine Hannover, Foundation, Busum, Germany Department of Small Mammal, Reptile and Avian Medicine and Surgery, University of Veterinary Medicine Hannover, Foundation, Hannover, Germany. Center for Animal Health, Baden-Baden, Germany Institute of Zoology, University of Veterinary Medicine Hannover, Foundation, Hannover, Germany Department of Pathology, University of Veterinary Medicine Hannover, Foundation, Hannover, Germany Nephropathology Unit, Institute of Pathology, Hannover Medical School, Hannover, Germany Reference Center of Amyloid Diseases, amYmed, Munich, Germany Department of Small Animal Medicine and Surgery, University of Veterinary Medicine Hannover, Foundation, Hannover, Germany Department of Small Mammal, Reptile and Avian Medicine and Surgery, University of Veterinary Medicine Hannover, Foundation, Hannover, Germany Introduction: Captive tree shrews (Tupaia belangeri) are widely used as experimental models for neurological, visual, and infectious disease studies. Despite evidence suggesting a genetic or physiological predisposition to systemic amyloidosis in this species, its clinicopathological characteristics are still poorly understood. The present study aimed to characterize clinicopathological changes associated with systemic amyloidosis in a captive breeding colony of Tupaia belangeri (T. belangeri) and to explore potential early ante-mortem indicators in blood indices, imaging, or clinical examination of the disease. Materials and methods: Nineteen T. belangeri were included in the present study (seven males, 12 females) with a mean age of 3.3 years from a single institutional breeding colony at the University of Veterinary Medicine Hannover, Germany. Fifteen animals underwent standardized ante-mortem clinical assessment, including physical and ophthalmic examination, serum biochemistry, urinalysis, radiography, and abdominal ultrasonography, followed by necropsy and histopathology. Four animals were included solely on the basis of pathological and histological examination due to long intervals between the prior clinical evaluation and necropsy. Amyloid was identified histologically by Congo red staining and confirmed as AA-type by immunohistochemistry. Results: Systemic AA-amyloidosis was detected in 74% of the examined T. belangeri (14/19), predominantly affecting the kidneys and intestines. A significant association was observed between renal cysts and amyloid deposition. An association with urine specific gravity was observed, while no significant associations were identified between amyloidosis and other biochemical, urinary, radiographic, or ultrasonographic parameters, nor with sex, body weight, or age. Conclusion: Systemic AA-amyloidosis appeared to be common in captive T. belangeri, predominantly affecting the kidneys and intestine, while lacking reliable ante-mortem clinical or laboratory indicators, highlighting the need for improved diagnostic approaches. https://jlar.rovedar.com/index.php/JLAR/article/view/88 AA-amyloidosis Animal model Protein misfolding Tupaia belangeri