A system for observing and predicting a physiological state of an animal has been provided. The system includes a computer including a processor and being operatively connected to a database, at least one sample providing device for repetitively providing at least one sample of a body fluid of the animal, an analysis apparatus for analysing the at least one sample, so as to obtain at least one sample value of at least one parameter of the body fluid, a data interface for repetitively entering the sample value of the at least one parameter in the database, where the database is adapted to store multiple database entries representing the sample value of the at least one parameter at various points in time, and where the processor is programmed to perform at least one mathematical analysis of the at least one sample value, and selecting, on the basis of the at least one mathematical analysis, the point in time for providing a subsequent sample and performing a subsequent analysis of the subsequent sample for at least one of the parameters.