Diarrhea is a common event in neonatal calves and can be caused by a wide v
ariety of infectious and noxious agents. Irrespective of the cause, the fin
al, and sometimes fatal, result is dehydration and acidosis with a concomit
ant failure in bodily function. Diarrhea results in considerable economic l
oss and discomfort to the calf. These problems can be reduced or averted in
an economical fashion through appropriate oral fluid therapy. The details
of the metabolic derangements in diarrheic calves and the appropriate measu
res to correct them are both complex and fascinating. This review is an int
roduction to some of the more important concerns.