The remarkable decline of the packed cell volume (PCV) levels and the reduction of the red blood cell (RBC) count, accompanied by increased whole plasma and whole blood volumes after the intravenous injection of xylazine bydrochloride (Rompun) in rams, is principally regarded to be the result of an erythrocyte storage in the spleen rather than a dilution of the blood due to a shift of fluid from the interstitial region.