Epidemiology of ovine respiratory complex in lambs

Abstract Ovine respiratory complex is one of the main diseases affecting lambs in many countries. Similar to other multifactorial diseases, it is highly influenced by the combination of the different factors that influence the animal, such as the environment, the production system in which they are reared or the host factors themselves. For this reason, epidemiological data of this disease are variable according to the risk factors present in each region and even in each flock. In order to understand the different options available at farm level for the epidemiological study of the ORC, the authors present results from five different studies carried out during the last years in sheep meat production systems in Spain. These studies make different approaches to the measurement of the importance of the ORC, ranging from the assessment of clinical cases and observation of lesions during necropsy to more complete analysis such as data collection on condemnations at the slaughterhouse. This practical approach should allow to analyse in a simple way the incidence of the disease in a farm and its maximum risk moments of presentation, which will be absolutely essential to design preventive plans adjusted to each situation.