THE VISCOELASTICITY OF BLOOD AND PLASMA IN PIG, HORSE, DOG, OX, AND SHEEP

There is little data on blood viscosity in different animals. Therefor e a comparison was performed between five species by an in-vitro metho d using oscillatory flow. At shear rates from 1 to 150/sec the viscous and the elastic component of the complex blood viscosity was highest in pig, followed by horse, dog, ox, and sheep. Plasma viscosity and pl asma density were similar in dog and sheep and were higher in ox. The differences in whole blood viscosity were obviously related to the var iable interspecies hematocrit, and may also be influenced by different aggregation tendencies. Aggregation in ox was low despite a high plas ma fibrinogen. It seems that erythrocytes in sheep and ox remain separ ately suspended in a relative dense plasma. This may indicate that for mation of microthrombi is less likely to occur in ox and sheep than in pig, horse, and dog.