In the years between the announcement of their discovery by Wilhelm Konrad Roentgen, on December 28, 1895, and the present, x-rays have contributed greatly in advancing medical knowledge. In internal medicine, surgery and dentistry these rays have been of very great value in the practice of veterinary medicine as a diagnostic aid but until recently their importance and value in the practice of veterinary medicine and surgery have been little appreciated. Trained veterinary scientists, unfortunately, have made no concerted effort to apply x-rays in the study and diagnosis of animal pathology. It is the firm conviction, however, of those who have engaged in this work that its importance and value will increase as more experience is gained. The veterinary profession of recent years has become x-ray conscious and rightfully so, as there is an important, necessary, useful field for its use in veterinary medicine. However, the use of the x-ray is not entirely without its hazards.