In light of improving breeding advice, the frequency was estimated for all the disease-causing mutations that were known at the start of the study and that are potentially relevant for a group of dog breeds, which are relatively popular or in which the genetic diversity in Belgium is low to moderately low. In this study, the results for the German shepherd dog, Malinois, Lakenois, Groenendael, Tervuren, Australian shepherd and Border collie are presented. Disorders with a frequency high enough to warrant routine genotyping for breeding programs are (1) multidrug resistance 1 and hereditary cataract for the Australian shepherd, (2) degenerative myelopathy for the German shepherd dog, Malinois and Groenendael and (3) collie eye anomaly for the Border collie. In addition, the hyperuricosuria mutation described in the German shepherd dog was not found in its Belgian population, but was, to the authors' knowledge discovered for the first time in the Malinois.