The project will use reliable state-of-the-art genomic technologies for the rapid identification of genetic markers for heritable diseases in horses, which will facilitate effective genomics based selection against disease susceptibility. The diseases of particular focus for this project are osteochondrosis (OC), insect bite hypersensitivity (IBH) and chronic progressive lymphedema (CPL). The occurrence of these diseases is a significant problem for horse owners and breeders and leads to poor animal welfare and severe economic losses. The initiative of this project is mainly based on the strong wish from the studbooks to obtain a genetic alternative to the more traditional breeding methods which are often not feasible in the smaller breeds. For each disease, a genetic component to disease susceptibility has been confirmed and several research groups in Europe have independently carried out small to medium-sized studies in order to find the causative genetic mechanisms underlying the disorder. However, the mode of inheritance for these diseases appears to be complex, and no genes or mutations have been identified yet, suggesting that analysis of much larger sample sizes is required or across datasets. This project aims to bring together the efforts of European research groups that are currently working on the genetics of disease susceptibility in horses. This collaboration will enable the groups to pool data for meta-analysis leading to more rapid progress in the identification of the genes and suitable gene markers for use in genomic selection against disease susceptibility. The SME associations, in close collaboration with the RTD performers, will develop breeding strategies that are optimized to the specific situation of that SME association. Once genetic markers are found, these markers will be implemented in the breeding programs of the different SME associations and can be commercialized. This will improve the competitive position of the SME partners represented by the associations. The breeding organisations will have direct access to the tests through commercial labs and through the labs they already collaborate with for their parentage control.