First of all, we recommend the EM (efficient micro organisms) to help the intestinal flora (where there is a synthesis of many vitamins and nutrients). A good flora will allow a better assimilation of vitamins, minerals, trace elements (http://horseremedy.eu/fr/micro-organismes-efficaces/8-proferm.html). If your horse has a good quality hay, an adapted food, if he doesn't have any particular physical problem and a good intestinale base we don't see why we would complement. Our philosophy is that if the bases are good, the body will do his work correctly. If there's a particular issue to treat, don't hesitate to contact us.