In recent years several "new" infectious agenLs have been associated with neonatal diarrhoea in both calves and pigs. Furthermore, important additional information has become available as regards enterotoxigenic Escherichia coli infec tions in both species. Although still much has to be learned, it is likely that in many field cases differnt agents act in concert. Therefore an integrated approach to the problem of neonatal diarrhoea appears to be necessary, particularly in the field research. Such an approach requires a series of diagnostic techniques. The purpose of this meeting was to bring together a limited number of scientists that are actively involved in neonatal diarrhoea research, in order to discuss present knowledge and to produce proceedings containing review articles, new developments and laboratory manuals of relevant diagnostic techniques. x This publication constitutes a collection of scientific pa pers and laboratory manuals on diagnostic techniques for en teropathogenic agents in neonatal diarrhoea in calves and pigs, presented and discussed during a workshop in the EEC Program me of Coordination of Agricultural Research on Protection of the Young Animal against Perinatal Diseases, held at the Central Veterinary Institute, Department of Virology, Lely stad, the Netherlands, June 3-5, 1980. VIRAL AGENTS ASSOCIA1ED WIlli NEONATAL DIARRHOEA AND TIlEIR DE1ECTION BY ELECTRON MICROSCOPY M. S. McNulty, W. 1. Curran and J. B. McFerran Veterinary Research Laboratories, Stormont, Belfast, BT4 3SD, N. Ireland ABSTRACT Simple techniques for diagnosis of enteric viral infections by direct electron microscopy of faeces are described.