Ehrlichia canis or a closely related rickettsial organism has been implicated serologically and morphologically as the causative agent of human ehrlichiosis in the United States. Although E VSports手机版. canis has been serially propagated in primary canine monocytes, only a limited quantity of antigen is obtained by this method. A continuous canine macrophage cell line, DH82, supports the growth of a new isolate of E. canis established from the whole blood of a carrier dog in Oklahoma. Serologic comparison of the Oklahoma isolate in the continuous canine cell line with a Florida isolate in commercial antigen slides revealed 100% specificity and 87. 5% sensitivity. .