Ostrich leg and toe disease causes substantial morbidity and economic losses; however, its etiology and pathological progression remain poorly understood and inadequately controlled. This study aimed to investigate pathological changes in the cartilage and subchondral bone of the metatarsophalangeal joint in ostriches with leg and toe disease, with particular emphasis on the expression of key inflammatory mediators. Eighteen 30-day-old male ostriches were divided into three groups (n=6 each): H (healthy), D1 (mild disease), and D2 (severe disease). Pathological changes were evaluated using hematoxylin–eosin (HE) and Masson’s trichrome staining. The expression of IL-1β, MMP-7, LOXL2, and COL2A1 was analyzed at the mRNA level by quantitative reverse-transcription PCR (qRT-PCR) and at the protein level by immunofluorescence (IF) and enzyme-linked immunosorbent assay (ELISA). Joint effusion volume and metatarsophalangeal circumference were also measured. Compared with the H group, the D1 and D2 groups showed significant increases in joint fluid volume (D1 vs H, P<0.01; D2 vs D1, P<0.01) and joint circumference (D1 vs H, P<0.01; D2 vs D1, P <0.05). Histological examination revealed fragmentation of collagen fibers in the superficial cartilage, a reduction in chondrocytes in the middle layer, and loosely arranged trabeculae in the subchondral bone. IL-1β and MMP-7 were progressively upregulated at both mRNA and protein levels with increasing lesion severity (IL-1β: P <0.01; MMP-7: P <0.01). In contrast, LOXL2 and COL2A1 were progressively downregulated (LOXL2: P<0.01; COL2A1: D1 vs H, P<0.01; D2 vs D1, P<0.05). These findings demonstrate that the progressive upregulation of IL-1β and MMP-7, together with the downregulation of LOXL2 and COL2A1, is closely associated with lesion severity, suggesting that these mediators may play key roles in the pathogenesis of ostrich leg and toe disease and may serve as potential targets for therapeutic intervention.

To Cite This Article: Deng Y, Duan B, Tang L, Wang R, Wang J, Chen Z, Fang J, Huang C, Liu W, Luo Q, Jia L, Geng Y, OuYang P, Guo H and Deng H, 2026. IL-1β/MMP-7/LOXL2/COL2A1 mediates the pathological damage of the metatarsophalangeal articular cartilage-subchondral bone in ostrich leg and toe disease. Pak Vet J, 46(4): 920-929. http://dx.doi.org/10.29261/pakvetj/2026.068