The dog as a hemorheological model

The rheological properties of the blood and its components depend greatly on the flow conditions. Because of the complexity of hemodynamic conditions and the rheological properties of blood, it is almost impossible to obtain information which is directly relevant to in vivo rheological behaviour of blood by ex vivo studies only. The effects of rheological alterations on the overall hemodynamic picture should be tested in the living bodies in order to be able to include all of the above mentioned complexities. Under experimental conditions the easiest way to do this is by using an animal model. The dog as an experimental animal seems to be the most extensively studied hemodynamic model. There is a large collection of published data on the dynamics of blood flow in general and the specific circulatory systems of the dog including well developed mathematical models. However these models do not include hemorheological parameters and should be extended to cover the role of the rheological behaviour of the blood.