Records of lame horses (2004-2007) with (peri-)synovial pain of the metacarpophalangeal joint (MCPJ, n=53), digital flexor tendon sheath (DFTS, n=20), and distal interphalangeal joint (DIPJ, n=31) were evaluated (n=104). Cases were grouped according to the following treatments: (1) systemic administration of NSAIDs (n=40); (2) intrasynovial administration of glucocorticosteroids (n=30); (3) combination treatment (n=34). Outcome was defined as successful when the owner reported that the horse had returned to its previous level of performance within a period of up to six months after treatment. Statistical evaluation was performed using Fisher's Exact tests and multivariable logistic regression analyses at P < 0.05. Successful outcome was significantly higher for horses in treatment group 3 (19/34, 55.9 per cent, P=0.021) than in treatment groups 1 (11/40, 27.5 per cent, OR 0.21, 95 per cent CI 0.06 to 0.71) and 2 (8/30, 26.6 per cent, OR 0.18, 95 per cent CI 0.06 to 0.56). A significant association was only found with regard to the affected synovial structure (P=0.025); relative to the DIPJ, involvement of the MCPJ and DFTS was four to five times more likely to provide a successful outcome (OR 4.18 and 5.59, 95 per cent CI 1.24 to 14.08 and 1.42-22.22, respectively).