Clinical Evaluation of Intra-articular Administration of Stanozolol to Manage Lameness Associated With Acute and Chronic Osteoarthritis in Horses

•Veterinary practitioners selected horses, all showing clinical signs of acute or chronic osteoarthritis.•The clinicians administered one to four (acute cases) or one to six (chronic cases) weekly intra-articular doses of 5 mg of stanozolol or placebo.•Stanozolol injected intra-articular at a dose of 5 mg significantly improved lameness in affected joints.

Poor data could be found in the literature on the effects of intra-articular (IA) administration of stanozolol in horses affected by osteoarthritis (OA). To verify the clinical effects of IA stanozolol in acute and chronic cases of OA in horses, a clinical double-blinded trial involving 60 client-owned horses was performed. Veterinary practitioners selected horses, all showing clinical signs of acute or chronic OA, diagnosed in a single joint. After lameness evaluation and synovial fluid collection, the clinicians administered one to four (acute cases) or one to six (chronic cases) weekly IA doses of 5 mg of stanozolol or placebo. Positive result was considered a grade 1 improvement in lameness scored according to the American Association of Equine Practitioner scale. The characteristics of the synovial fluid were also evaluated. Of the 60 horses included in the study, 31 were affected by acute OA and 29 by chronic OA. Horses were treated blindly with placebo. The overall outcomes were positive in 82.50% of cases. Lameness disappeared completely in 15 of 21 (acute) and 11 of 19 (chronic) animals, and there was a significant reduction after two and four treatments, in the acute and chronic cases, respectively. Improvement in the physical characteristics of the synovial fluid sampled was evident after the third treatment. Stanozolol injected IA at a dose of 5 mg significantly resolved lameness in affected joints. Stanozolol could be considered a safe option for the treatment of horses suffering from OA.