Lameness is an indicator of pain and suffering, which has substantial animal welfare and economic impact on the dairy industry. Subjective locomotion scoring is unreliable for detecting mild cases of lameness in dairy herds. Undetected lameness can progress to a more serious and painful state with unfavourable prognosis. The aim of this study was to conduct an investigation on the use of a pressure plate for early detection of lameness in dairy heifers compared to a subjective visual scoring system. Seven heifers deemed sound, on the basis of a visual scoring system, were walked through a chute where a pressure plate was disguised on the floor. Claws were then inspected during trimming and revealed no lesions (n = 3) and hairy heel warts on at least one hind claw (n = 4). Peak vertical force (PVF) and right-left hind limb PVF symmetry were calculated. Sound heifers demonstrated significantly higher PVF and better right-left hind limb symmetry than those with hairy heel warts. Using a pressure plate, gait abnormalities from foot lesions that were undiagnosed using a subjective lameness scoring system, were detected. Early detection of lameness is vital to reduce dairy industry losses and to improve animal welfare.