Bronchopneumonia in calves (and young cattle) remains a significant problem despite advances in animal production and veterinary medicine. Bronchopneumonia is a polyfactorial disease (as is mastitis in dairy cows). It occurs when three basic influences combine: unfavourable external conditions, insufficient immunity of the animal and the action of a pathogenic agent (in a significant infectious dose). Proper recording of the occurrence of diseases in livestock is the basis for successful breeding work. This applies especially to diseases such as bronchopneumonia in calves, which is characterised by low heritability. This puts breeders in a situation where only a reliable estimate of the breeding value for resistance to this disease is applicable for selecting resistant parents of the next generation of dairy cattle. The work mapped the health data of calves in the area of ​​infectious diseases of the respiratory system. Bronchopneumonia, unsurprisingly, completely dominated. More broadly, it was recorded in the Diary in approximately 9-12% of calves, overall for 7.5 years of online recording and individual years. The results of further analyses by breed together with gender, size of herd, etc., showed the complexity of the relationships and the need to consider other factors, such as the length of time the calf has been in the herd. However, for approximately 1.5 years, breeders and their services have had the opportunity to have a more analytical insight into slightly more general diseases of the respiratory system in the web application, Comparison of morbidity covered by the application, Access to data of ČMSCH, a.s