Chemical and immuno-chemical test kits are frequently used in human medicine for the detection of fecal occultblood loss. Since only limited data on the use of these test kits in equine medicine are available, the chemicalHemoccult SENSA test was evaluated for the detection of fecal occult blood loss in the horse. The results show thatthe Hemoccult SENSA test kit has a good sensitivity and specificity for the detection of distal intestinal blood lossin stabled horses. In horses at pasture, many false positive reactions were observed, probably due to the presence ofplant peroxidases in the diet. This high rate of false positive reactions could, in contrast to the human analyses, notbe eliminated by a delayed development of the test. Stabling the horses for at least four days before testing drasticallyimproved the specificity. In comparison to humans, the detection limit of the Hemoccult SENSA test appears to belower in horses. In the present study, up to 1% of the blood loss could be detected in the feces. This corresponds to120 ml blood loss a day.