Effect of dietary factors on the detection of fecal occult blood in cats

Eight different diets were each fed to 6 cats to evaluate the effect on a g uaiac and an o-tolidine fecal occult blood test. Fecal samples were collect ed from day 5 through day 7. Canine blood or pure cottage cheese were used as positive and negative controls, respectively. One hundred thirty-four fe cal samples were analyzed. The dry fish (capelin) and vegetable (tapioca) d iet and the pure cottage cheese diet had only negative results in both test s, whereas a canned chicken and cereal (rice) diet had negative results in all fecal samples in the o-tolidine tablet test and in 10 of 16 fecal sampl es in the guaiac paper test. All other fecal samples from cats eating 6 oth er diets and the canine blood additive were positive in both fecal occult b lood tests. These results indicate that occult blood tests based on o-tolid ine and guaiac are clinically useful, but cats need to be on a strict diet before the tests are used.