Efficacy of Flunixin Meglumine and Dimethyl Sulfoxide in Ameliorating Endotoxemia in Donkeys (Equus asinus): Insights from NGAL and B2M Biomarker Dynamics.

Endotoxemia is a critical clinical challenge in donkeys (Equus asinus), yet species-specific studies on therapeutic management and early diagnostic markers remain limited. This study evaluated the comparative efficacy of flunixin meglumine (FM) and dimethyl sulfoxide (DMSO) in an experimental asinine endotoxemia model and investigated serum neutrophil gelatinase-associated lipocalin (NGAL) and β2 -microglobulin (B2M) as early biomarkers for subclinical acute kidney injury (AKI). Twenty-four healthy adult jennies were randomized into four groups (n=6): Control group (CG: 0.9% NaCl IV), lipopolysaccharide (LPS) group (LPS-G: 3µg/kg IV), flunixin group (FM-G: LPS + 1.1mg/kg FM IV), and DMSO group (DMSO-G: LPS + 0.5g/kg DMSO IV). Clinical, hematological, biochemical, and oxidative stress variables were monitored sequentially over 6hours. LPS infusion successfully established systemic inflammatory response syndrome (SIRS). While neither treatment aborted initial hyperacute cardiopulmonary surges, FM significantly accelerated abdominal pain resolution, preserved gastrointestinal motility, and restored appetite earlier than DMSO (P <0.05). Serum NGAL and B2M concentrations surged within 1 to 2hours post-infusion and peaking sharply at T4 prior to serum creatinine alterations. FM treatment significantly blunted acute-phase NGAL elevations (T1-T4, P <0.05) and accelerated B2M clearance back to baseline. Both therapies mitigated oxidative stress, with FM acting earlier. In conclusion, FM demonstrated superiority over DMSO in alleviating visceral pain, preserving intestinal motility, and dampening subclinical renal tubular stress in endotoxemic donkeys. Serum NGAL and B2M could likely consider sensitive, ultra-early biomarkers for subclinical AKI in asinine critical care.