Plasma coagulation in mammals shows an essentially uniform structure. Differences are in species specific composition and quantity of coagulation factors. Many of the coagulation disorders occurring in humans have been observed in other mammals. Almost all the coagulation studies performed to date have been in domestic animals. For the majority of mammalian species, e.g. zoo animals, therefore, we have either no data at all or only isolated results. The methods used for coagulation testing in veterinary medicine have not yet been standardized. The significance and informative value of the screening tests are limited in animals compared with humans. The activities of individual factors in animals are determined by coagulometric tests. The results can be determined in relation to the activity in humans with the help of a human normal plasma or in relation to the activity of the respective animal with the help of a normal plasma from the same species. The problem is the parallelity of the dilution curves used as reference curves. The coagulation factor activities given for mammals usually differ more or less markedly from those in humans.