Using systemic serum amyloid A as a biomarker for synovial structure infections in horses with acute limb wounds

In postoperative monitoring of synovial structure infection due to limb wounds, early recognition of a recurrence of synovial infection is indispensable to prevent further damage to the affected synovial structure. This study evaluated the role of serum amyloid A (SAA) as a systemic biomarker in disease monitoring and correlated this tool with clinical variables.

In this prospective cohort study, 55 horses with acute limb wounds were divided into two groups: those with (group 1, n = 26) or without (group 2, n = 29) a diagnosis of synovial structure penetration. SAA, lameness and body temperature were evaluated repeatedly and compared between groups. Correlations were explored between SAA and body temperature as well as lameness. The long-term outcome was also analysed.

In both groups, SAA levels followed the characteristic rise-and-fall pattern observed in previous studies, with a significant increase up to a peak concentration within 48 hours, followed by a constant decline. Lameness and body temperature did not change significantly. SAA was not found to correlate with clinical variables at all time points. Three horses in group 1 had a recurrence of synovial sepsis with an associated increase in SAA. The long-term outcome was good. A total of 71% of the study population returned to pre-injury performance levels.

Repeated measurements of SAA accurately reflected the course of synovial inflammation and thus provided a reliable and rapidly available tool to monitor the disease course and to adapt the treatment regimen. SAA should be routinely added to the postoperative management of such cases.