In rabbits calcinosis was induced experimentally by feeding of Trisetum flavescens or Vitamin D3 injections. Calcifications in kidneys and lungs were proved by biopsies and x-ray examination respectively. Histological examination at intervals up to 26 months following the calcinogenic insult indicated signs of limited reversibility of calcification in lung, kidney and aortic wall. The degree of resorption of calcified deposits apparently was dependent on dosage, time and kind of tissue affected. Aortic wall and tendons had the least tendency to demineralisation and developed focal cartilage metaplasia. Two cows with proven enzootic Trisetum-calcinosis were kept under altered conditions for 31 and 32 months. At slaughter besides severe calcification and cartilage or osseous metaplasia in soft tissues a limited reabsorption of the calcifications could be observed. There were focal fibrous scars in the aortic wall.