LCN2 and synovitis: Increased blood levels of NGAL were demonstrated in horses with naturally occurring and experimental inflammation [20,21,22], and a recent study reported increased concentrations of NGAL in SF after experimental induction of joint inflammation (by intraarticular injection of lipopolysaccharide [LPS] or local analgesics) and in a small (n = 10) group of horses with naturally occurring septic synovitis [20].