Background: Septic arthritis affects ruminant welfare because, if left untreated, it can cause chronic pain and limit the mobility of affected joints.Objectives: This study aimed to investigate the clinical and pathological changes in arthritic bovine calves. Methods: The study was conducted on 12 calves with swollen knees or carpal joints. All calves were evaluated through clinical, radiographic, and ultrasonographic examination. Peripheral blood was aspirated from each to assess hematobiochemical changes. Synovial fluid and infected swab samples were subjected to bacteriological analysis, and a synovial biopsy was taken for histological examination. Results: Ultrasound revealed inflammatory effusions with various echogenicity in the afflicted joint capsule, while radiography showed remarkable swelling of joints and surrounding structures and the development of new bone. Regarding hematological variables, the value of total erythrocyte count, total leukocyte count, and erythrocyte sedimentation rate significantly (P<0.05) increased in septic arthritic calves compared to healthy calves. In the arthritis group, the serum concentration of alanine transaminase, alkaline phosphatase, and aspartate aminotransferase was considerably (P<0.05) higher than in healthy calves. The total protein and urea values were significantly (P<0.05) decreased in calves with infected arthritis. From the synovial fluid and purulent discharge of the joints, Staphylococcus aureus and Escherichia coli were isolated. Histopathology of synovial tissue revealed chronic suppurative inflammation with intense hyperplasia of joint synovium.Conclusion: The results of this study may aid veterinarians in effectively diagnosing and treating septic arthritis in calves.