The development of the 'chip' tends to make data-processing apparatus increasingly smaller, reliable and cheaper. The question is in which fields they will be of practical use to the veterinarian. In the present paper, a brief technical introduction is followed by a description of the functional potentialities and limitations of computers. The use for administrative purposes and recording as well as for interaction in processes of decision is discussed and illustrated by examples. The principles which are of importance in Information Retrieval and diagnosis are discussed. Finally, a data-processing system designed for veterinary practitioners is described in broad outline.