The objective of this research work were to 1) serially evaluate the immune function of experimentally manipulated dogs to define the time required to normalize immune function; 2) identify immunologic lesions produced by the experimental protocol which causes a delay in recovery of immune function; and 3) define method of restoring immune function through the use of immune enhancing agents. Keywords: Radiation effects; Whole body irradiation; Escherichia coli; Sepsis; Military medicine; Medical research.