Abstract
Trypanosoma evansi is a vector-borne protozoan parasite responsible for surra, a disease that affects a wide range of domestic and wild animals, causing severe health consequences and significant economic losses. This study aimed to investigate the histopathological effects of T. evansi infection in rabbits under controlled experimental conditions and assess the potential of rabbits as a suitable model for studying this disease. Sixteen rabbits were divided into infected and control groups. The infected group received an inoculation of T. evansi isolated from cattle. Clinical signs were monitored, and tissue samples from the liver, lungs, spleen, myocardium, and kidneys were collected for histopathological evaluation. Microscopic analysis revealed marked pathological changes in infected animals, including granular and fatty degeneration of hepatocytes, hyperemia, emphysema and exudative inflammation in the lungs, myocardial dystrophy, spleen hyperplasia, and degenerative changes in renal tissue.These alterations reflect systemic involvement, indicating the pathogenicity of T. evansi and its ability to affect multiple organ systems. The experimental model reproduced classical features of the disease, such as anemia, tissue edema, and hemorrhages, supporting the relevance of rabbits as a viable model for trypanosomiasis research. This study contributes to a better understanding of host-pathogen interactions and pathogenesis in surra. The results offer valuable insights for the development of diagnostic tools, treatment strategies, and vaccine research. Moreover, the established rabbit model may facilitate future investigations into the biology and virulence of T. evansi strains circulating in Kazakhstan and beyond.