Evaluation of the clinical efficacy of repeated intra-articular injections of stanozolol in canine patients with spontaneous osteoarthritis

The study aimed to assess the clinical efficacy of repeated intra-articular (IA) administration of stanozolol for the management of spontaneous osteoarthritis (OA) in dogs. Clinical, radiographic, and synovial fluid cytological parameters were compared among dogs treated with IA stanozolol, IA hyaluronic acid, or oral mavacoxib (Trocoxil). Seventy-five client-owned dogs affected by unilateral OA were randomly assigned to three study groups of 25 dogs each: the stanozolol group (S), the hyaluronic acid group (HA), and the mavacoxib group (T). Dogs received either three IA injections of stanozolol or hyaluronic acid administered at two-week intervals, or oral mavacoxib (2 mg/kg) administered on days 0 and 15, followed by monthly administrations for a maximum of four doses. Clinical, radiographic, and synovial fluid (SF) cytological evaluations were performed at baseline (T0) and on days 15, 30, 60, 90, and 180 after the initiation of therapy (T15, T30, T60, T90, and T180, respectively). The following parameters were assessed and statistically analyzed: Canine Brief Pain Inventory (CBPI), including the Pain Severity Index (PSI) and Pain Interference Index (PII), lameness score, visual analogue scale (VAS), GAIT4Dog lameness score (GLS), total pressure index percentage (TPI%), range of motion (ROM), limb circumference (CRF), radiographic OA grade, and SF cytology score (SS). The following parameters were assessed and statistically analyzed. Statistical significance set at p < 0.05. Data from 59 dogs (59 joints; 26 males and 33 females; mean age 7.7 years; mean body weight 28.6 kg) were included in the final analysis: group S (n = 22), group HA (n = 20), and group T (n = 17). Statistical comparisons revealed significant improvements in PSI, PII, and lameness score in the S group at 60 and 180 days compared to baseline; improvements in VAS and SS were also observed at T30, while GLS showed significant improvement from the first follow-up (T15). The results demonstrated greater improvements in several clinical outcome measures, including pain scores, lameness, GLS, and synovial fluid cytology, compared with the other treatment groups. In conclusion, repeated IA administration of stanozolol was associated with clinically relevant improvements in dogs with OA and may represent a promising therapeutic option for the management of canine OA.