The common laboratory mouse (Mus musculus, Mus domesticus), the rat and the hamster are members of the animal order of rodentia. Rodentia are estimated to have first appeared on earth about 63 to 58 million years ago (mya), much earlier than other mammals, which first appeared 25–2.5 mya, or early humans (~ 2.5 mya). Because of its small size, high fertility, and exceptional reproductive capacity, the mouse is very often used as an inbred animal species for biological research purposes. The same reasons, coupled with the extensive knowledge of the mouse genome, have made the mouse very useful in the development of gene targeting techniques (1). Disruption or “knockout” in mice of genes known to be associated with human disease states or biological functions, has been enormously successful in providing vital physiologic and pathologic information. It has also permitted investigations that cannot easily be performed in humans, thus speeding the assessment of therapeutic interventions. In order to exploit fully the opportunities presented by such animals it is important that the mouse’s homeostatic systems be defined, so that their similarities to, and differences from, the comparable human systems can be appreciated.

Our understanding of the hemostatic system has already been improved significantly by the availability of mouse models of human disease and by the knocking-out of genes that have not yet been identified as abnormal or missing in humans. Moreover, since elements of the hemostatic system may also participate in inflammation, oncogenesis, metastasis, and infectious diseases, it is important to have a clear understanding of the hemostatic system in the mouse in order to be able to interpret mouse models of these disorders most accurately. A wide spectrum of data about mouse hemostasis is available in the scientific literature, but they are fragmented and dispersed in numerous experimental settings. The aim of this review is to integrate the available data so that our current understanding, as well as the gaps in our understanding, are defined.