[Correlation of a lameness scoring system and claw lesion]

The aim of this study was to investigate the relationship between lameness scoring and clinical findings. The lameness scoring and a gait assessment took place during drying off, the first week after calving and two months after calving in 29 lame and 27 free of lameness cows. In between the farmer scored the lamness. Most of the lameness occurred in the hind limbs and were most frequently caused by dermatitis digitalis, Mortellaro, Limax, and Rusterholz sole ulcer. The mean duration of lameness after treatment was 26 days (median 16 days) and was significantly longer in case of horn lesions than in skin lesions (including interdigital dermatitis). Lameness- free control animals were often affected by heel horn erosion and digital dermatitis. It was shown that the sensitivity of lameness (lameness is caused by a certain aetiology) for a certain cause of lameness (dermatitis interdigitalis, doble sole, purulent hollow wall, Limax, digital dermatitis, Rusterholz sole ulcer and sole contusion) increases along with the threshold (degree of lameness) but that the specificity (no lameness is not related to a certain aetiology) remained constant at the same time. The highest sensitivity was achieved in injuries, followed by interdigital hyperplasia. The receiver operating curve (ROC) showed that lameness was the best selecting symptom in white line lesions followed by claw injury. The positive predictive values varied between 38.8% in white line lesions and 0% in Rusterholz's sole ulcer. The negative predictive values varied between 99.1% in interdigital dermatitis and 82.3% in interdigital dermatitis. The ROC analysis shows which lameness is more related to a certain claw disease. The results demonstrate, that a lameness score cannot be linked to a certain claw disease.