[Etiology, prevalence and evidence-based therapy and prevention of periparturient hypocalcemia].

Periparturient hypocalcemia is a frequently observed metabolic disorder in fresh cows. While the clinical form affects approximately 7 % of German dairy cows, nearly half of the multiparous cows exhibit subclinical hypocalcemia. Although both diagnosis and therapy have not changed over the last three decades, some farmers and practitioners are still unaware about the prevalence of and risk period for subclinical hypocalcemia. Moreover, various recommendations exist concerning the amount of calcium that is to be administered intravenously to a cow experiencing clinical signs of hypocalcemia. This article reviews the causes and prevalence of periparturient hypocalcemia. The aim is further to summarize the results of studies investigating therapy of clinical hypocalcemia in order to provide an evidence-based recommendation on the treatment of recumbent cows. Despite the high prevalence of hypocalcemia, it has been shown that the majority of German farmers do not implement preventive strategies against hypocalcemia. Therefore, we furthermore describe preventive strategies that may be useful in reducing the risk of hypocalcemia, based on what is known from the current literature.