Objective: The aim of the study was to investigate the rate of the different causes of parturient paresis in dairy cows in different regions of Germany. Material and methods: In four veterinary practices (A-D) in different regions of Germany, 764 cows which became recumbent around parturition were included in the study for a period of one year. After recording the case history, all animals were examined clinically. Before any treatment serum samples were taken from the jugular vein to measure the concentrations of calcium, phosphorus, magnesium, bilirubin, beta-hydroxybutyrate, cholesterol, urea and the activities of AST, GLDH and CK. In each practice the control therapy consisted of the intravenous infusion of an organic calcium solution,which was supplemented in every second cow (test group) with another drug (B: Vitamin D-3; C: Toldimfos; D: Dexamethasone). In Practice A, the calcium solution was replaced by another which contained 1.2 g phosphorus in addition, Results: Independent of the region, hypocalcaemia was found to be the major cause of paresis in parturient cows of the second lactation or older. The majority of these cows also had hypophosphataemia. Muscle damage was the second frequent diagnosis in parturient cows and the major concomitant disease in cows with hypocalcaemia. The use of an additional drug beside the organic calcium solution did not influence the success rate after first treatment, the overall rate of healed animals and the number of treatments needed. The success rate after first treatment ranged between 70.7 and 84.2%, and the overall rate ranged between 87.5 and 95.2%. Cows which could not be healed had significantly higher serum activities of CK (p < 0.020) and AST (p < 0.003) before the first treatment. In contrast to older cows, muscle damage was the major cause of recumbency in heifers. It could not be clarified in each case whether these damages were the result of dystocia or nerval lesions. Conclusions and clinical relevance: From the second lactation on, hypocalcaemia is the major cause of paresis in parturient cows in the peripartal period. Therefore, an intravenous infusion of an organic calcium solution is the therapy of choice. Additional drugs are not useful. Muscle damage is a frequent concomitant disease and may have a negative stake in the success of therapy. In heifers muscle damage is the major cause for recumbency.
