The Viscosity of the Blood of the Dog after Obstruction of the Upper Gastrointestinal Tract

Estimations of the viscosity of the whole blood and plasma of the dog after experimental upper gastrointestinal tract obstruction are reported. With cardiac obstruction there is a rapid and marked rise in the viscosity of the whole blood and some increase in the viscosity of the plasma. The changes after pyloric obstruction are similar to those observed after cardiac obstruction. After obstruction of the upper jejunum only slight changes are observed. The increase in viscosity parallels quite closely the degree of the toxemia. It is unaccompanied by any marked concentration of the blood.