2017 by John Wiley & Sons, Inc. The anatomy of the distal limb creates unique challenges with regards to blood flow regulation, specifically regarding venous return from the hoof capsule to the heart. It is thought that palmar digital veins may contribute to the regulation of blood flow via the maintenance of vascular tone. Recognizing the need to measure lamellar blood flow in horses, investigators have employed several techniques including laser Doppler flowmetry, arteriography, nuclear scintigraphy, thermography, and infrared spectroscopy. Laser Doppler flowmetry has been used in studies to detect fluctuations in lamellar blood flow during the prodromal stages of black walnut extract (BWE)-induced laminitis in horses and during the administration of a low dose of endotoxin to normal horses. Hemodynamic studies utilizing palmar digital veins and arteries have contributed significantly to the present understanding of digital hemodynamics. However, the results of these studies are difficult to interpret in the context of laminitis pathogenesis.
