Lamellar perfusion and energy metabolism in a preferential weight bearing model

Background Supporting limb laminitis (SLL) is suspected to be caused by lamellar ischaemia as a consequence of increased mechanical load. Objectives Examine the effects of prolonged preferential weight bearing (PWB) on lamellar perfusion and metabolism. Study design In vivo experiment. Methods Microdialysis probes were inserted in the lamellar and sublamellar dermis of one forelimb in 13 Standardbred horses. In six horses, a platform shoe (contralateral forelimb) was used to induce increased load on the microdialysis‐instrumented forelimb (PWB). The remaining seven horses were controls (CON). All horses were housed in stocks with limb weight distribution logged continuously for 92 hours. Microdialysate was collected and analysed every 4 hours for glucose, lactate, pyruvate, and lactate to pyruvate ratio (L:P). Microdialysis urea clearance was used to estimate lamellar perfusion. Data were analysed using a mixed‐effects linear regression model. Results Median [IQR] load on the microdialysis‐instrumented limb was equivalent to 38.7% bwt. [37.3‐40.3] in PWB and 27.3% bwt. [26.6‐28] in CON. Limb offloading frequency increased in CON (P