[Histological study of cartilage channels in the epiphyseal cartilage of young dogs and their relationship to that of osteochondrosis dissecans in the most frequently affected locations].

Osteochondrosis is a disease occurring in many species of domestic animals. There are different factors like genetic predisposition, housing and feeding, trauma and stress, which are thought to be the causes or part of the causes of the disease. There have been studies about swine, finding a connection between cartilage channels in juvenile epiphyseal cartilage and the development of osteochondrosis. The aim of the study was to find out whether those connections exist in dogs as well. Special interest has been laid upon the localisation, the contents and the surroundings of cartilage channels as well as their relationship to the localisation of osteochondrosis. Joint surfaces, that are most often subject to osteochondrosis in the dog, have been examined macroscopically and histologically, e.g. the caput humeri, the medial part of the humeral condyle, the lateral condyle of the os femoris, the cochlea tibiae and the trochlea tali of 31 dogs at the age of three days to nine months. According to this examination cartilage channels can disturb the process of ossification of cartilage in the secondary centre of ossification, causing a thickening of cartilage layers. These changes can often be seen in locations, where osteochondrosis usually develops, especially in the caput humeri. Altogether they could be located more often in male animals and large breeds than in female animals and small breeds. To a certain degree these changes can be considered as normal in the development and growth of a young dog, but combined with other factors like trauma or stress, they may play a favoring role in the pathogenesis of osteochondrosis as well.