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).