Before a physical therapy and rehabilitation program is suggested, the end requirement must be considered. All physiotherapeutic machines are subject to laboratory screening. In the United States, the approval of the Food and Drug Administration is required; in the United Kingdom, certification by the National Physics Laboratory has been required by law since January 1996. Laboratory experiments are continually conducted to examine and evaluate the effects on tissues of varied electrical waveforms, low-intensity electrical currents, sound waves, and light rays delivered by a variety of therapeutic apparatuses. It is interesting to note that the tissues used for this work are derived from the rabbit, rat, and chick embryo. If these investigative procedures demonstrate benefit to tissue behavior following trauma in laboratory animals, they are then considered to be of benefit to humans. Surely, it must follow that equal benefit is to be derived by other species with similar tissues. Despite veterinarian prejudice to the contrary and by careful case selection rather than random application, horses can profit from the application of electrotherapy and derive benefit from rehabilitation; thus, an informed physical therapist should be considered a useful member of a "care" team. Because no two cases are ever the same, it is impossible to write a "recipe" book stating exactly the dosage, treatment time, or applications per week or per day. Success depends on an in-depth assessment of individual needs followed by an informed choice of therapy. In the case of physical therapy, this necessitates the use of the appropriate modality at the appropriate time, always taking into account the fact that tissue is living and is therefore in a continually changing state. The art of the physical therapist is to read the situation each time a patient is seen and to proceed according to the findings of the moment. The author regrets that there are no double-blind trials to quote or published research available to substantiate rehabilitation methods. The therapy principles relating to proprioceptive input, cortical re-education, muscle recoordination, and atrophy following both micro- and macrotrauma have been transferred in field work from humans to horses.