[Radiologic follow-up examination of podotrochlosis]

X-rays of 205 horses having navicular disease and having been reexamined up to six times are evaluated. For this, the x-rays of each foreleg are evaluated in the dorsopalmar (Oxspring) and lateromedial view. Additionally to changes of the navicular bone, changes of the distal part of the toe are also assessed. Differences can be found in the radiographic process in view of the limitation of vascular foramina and cyst-like lesions. Vascular foramina with sclerotic rim grow less frequent than poorly defined ones and therefore allow for easier prognostication. Cyst-like lesions with sclerotic rim often stay unchanged or decrease separately, whereas poorly defined areas of rarefication show a stronger tendency to expand into the surrounding spongiosa. Changes of vascular and bone structure occur already within a few months, whereas most of the margination changes are already formed in the early stages of disease and proceed slowly. Finally the effects of the therapy are being examined for the radiographic course of disease. Following a neurectomy, a more intensive development of the changes can be observed. The rate of only minimally altered navicular bones as well as the often simultaneous occurrence of changes in the joints of the toe do not allow for a diagnosis only on the basis of radiographic findings. The often slow development of the pathological radiographic changes requires intervals of examination of at least one year and shows that prognostic statements can only be made with caution even after follow-up examinations.