The main purpose of this study was to evaluate the effectiveness of an oral fluid therapy alone or combined with parenteral administration of a 5% dextrose solution to attenuate the clinical signs and the pathophysiological consequences of transmissible gastroenteritis in neonatal piglets. Eighteen two day old conventional piglets were infected with transmissible gastroenteritis virus while six others were used as controls (Group 1). At the onset of diarrhea, infected piglets were divided into three groups of six (Groups 2, 3 and 4). Piglets in group 2 were not treated and were fed a milk replacer ad libitum. Piglets in group 3 were removed from the milk replacer and placed on an oral glucose-glycine-electrolyte solution ad libitum. Those in group 4 were placed on oral fluid therapy and received a 5% dextrose solution intraperitoneally at the rate of 25 mL/kg of body weight once a day. Blood samples were collected in heparin within minutes after the infected piglets became comatose and from the controls at four or five days of age. The following variables were measured: packed red cell volume, blood pH, total plasma protein and bicarbonate, blood urea nitrogen, and plasma glucose, creatinine, chloride, inorganic phosphorus, sodium, potassium, magnesium and calcium. Vomiting and diarrhea appeared 12 to 24 hours postinoculation in the infected piglets. There was a sudden and rapid progression into a comatose and moribund state one or two days later whether the infected piglets were treated or not.(ABSTRACT TRUNCATED AT 250 WORDS)