Deworming programs rarely eliminate all of your horse’s parasites. The goal of most programs is to reduce the number of parasites each horse has and to reduce parasite contamination of common grazing or turnout areas. The efficiency of deworming programs can and should be evaluated by performing fecal egg counts. This is the only way to truly evaluate how effective your parasite control program actually is. With this information, adjustments can be made and you will go a long way in diminishing your chances of having a colicky horse.