Marwa S Khattab^1*, Alaa M Ali¹, Ahmed H Osman¹, Huda O AbuBakr², Rehab A Azouz³, Eman S Ramadan⁴, Heba S Farag⁴

Bovine papillomatosis (BP) is one of the imperative cutaneous oncogenic viral diseases resulting in leather depreciation and economic losses. This study aimed to evaluate oxidative stress, immunohistochemistry and ultrastructural alterations in BP and its impact on cowhide. Ninety skin tissue specimens and blood samples were collected from cattle. Hematological parameters including complete blood picture, copper and zinc concentration in sera and oxidative stress biomarkers in skin were evaluated. Sera were tested for bovine papillomatosis antibodies. Histopathology of all skin samples, immunohistochemistry of collagen 1 and gamma catenin were performed. Moreover, BP virus was identified by transmission electron microscope in papilloma lesions. Bovine sera tested were positive for bovine papillomatosis antibodies (28.8%). In diseased cases, a significant reduction in Cu and hemoglobin were recorded compared to normal animals. Protein oxidation and MDA were elevated whereas GSH and SOD were reduced in diseased cases. Histopathology of bovine skin lesions of papilloma infected cases showed finger-like projecting papillae and papilloma with overlying stratum corneum and acanthosis. Collagen I fibers were altered in papilloma's and fibropapillomas. Gamma catenin expression was translocated to the nucleus in many epidermal cell layers indicating desmosomes damage. In conclusion, BPV altered the host hematological parameters, oxidant/antioxidant balance toward oxidative damage, collagen, γ-catenin content, trace elements, especially copper, and the tensile strength of the skin. Therefore, BP decreased the quality of animal hide.