This study was intended to verify the clinicopathological effect of intra-articular (IA) staph aureus and amphotericin B injection in the carpal joints of donkeys to induce arthritic changes and to correlate it with the histopathological findings. Six healthy, adult donkeys of both sexes. Animals were numbered and divided into two groups; each group consists of three animals. 1^st group is used for induction of septic carpitis in the right radiocarpal joints of donkeys by Staph. aureus with a dose of 3×10⁶cfu as a single intra-articular injection.  The 2^nd group is used for induction of osteoarthritis in the radiocarpal joints of donkeys by 20 mg amphotericin B in 3 ml sterile water as a single intra-articular injection. Whereas the left joint was the control in both groups .Two ml Synovial fluid and serum were taken at 0, 1, 3,7,13 days after administration and tissues samples of Joint capsule and synovial membrane at 13 days. Sampling at zero daywas considered as control.  Clinical assessment, synovial fluid analysis,ultrasonography and histopathological examinations were done. Total leukocytic count, total protein Amyloid A, IL-1β and CRP concentrations sharply increased on 1, 3, 7, 13days 7 after induction of the experiment when compared with their control at zero. .There were significant changes in amyloid A, IL-1β and CRP in septic cases when compared with aseptic cases of arthritis. The results obtained confirm that the concentrations of total leukocytic count, total protein amyloid A, IL-1β and CRP increase substantially in equine septic arthritis and osteoarthritis which provides a theoretical basis for the rapid diagnosis of the diseases and to distinguish between septic arthritis and non-septic synovitis by a variety of diagnostics.