Effects of intra-articular injections of bufexamac suspension on amphotericin B-induced aseptic arthritis in horses

Objective-To evaluate effects of intra-articular (IA) injections of bufexam ac on amphotericin B-induced aseptic arthritis in horses. Animals-24 Standardbred horses. Procedure-Aseptic arthritis was induced in the right intercarpal joint by I A injection of amphotericin B (20 mg). One week later (day 0), horses were randomly assigned to four 6-horse treatment groups and treated with IA inje ction of 10, 20, or 40 mg of bufexamac suspension (20 mg/ml) or 2.0 ml of s terile saline (0.9% NaCl) solution (control). The treatment was repeated on ce after 7 days. Clinical lameness examinations and synovial fluid (SF) ana lyses were done prior to induction and at weekly intervals for 5 weeks (day s 0, 7, 14, 21 and 28). Results-Intra-articular injection of amphotericin B consistently resulted i n aseptic arthritis with a lameness index (mean +/- SEM; scale 0 to 5) of 2 .7 +/- 0.17 on day 0. Intra-articular Injections of 20 and 40 mg of bufexam ac significantly reduced the day-28 lameness index, compared with control v alues. Amphotericin B administration also resulted in a significant increas e in SF beta-glucuronidase (BGLUC) activity, and IA injections of bufexamac significantly reduced day-28 activity of this enzyme, compared with contro l values. Conclusions and Clinical Relevance-2 IA injections of 20 or 40 mg of bufexa mac, at weekly intervals, were effective in reducing clinical signs of lame ness and SF activity of BGLUC associated with amphotericin B-induced carpal joint arthritis. Bufexamac possesses anti-inflammatory properties useful f or IA treatment of lameness associated with aseptic arthritis in horses.