Fecal occult blood (FOB) testing provides a quick and easy way to screen patients for gastrointestinal bleeding. The sensitivity of the Hemoccult® FOB test kit has been recently evaluated for use in cats fed canine packed red blood cells. However, the development time for test interpretation and the limit of detection of fresh whole blood in a given stool sample has not yet been reported. Our goal was to determine the limit of detection of whole blood in a feline stool sample, as well as determine the most accurate time to assess the FOB sample utilizing the Hemoccult® testing kit in a population of cats.

Stool from recently dewormed, healthy, indoor cats were enrolled in the study. Two grams of stool from 3 separate cats that tested negative on the Hemoccult® FOB test were utilized as sample controls. Incremental quantities of EDTA whole blood (1–200 µl) were added to the 6 gram pooled stool controls. The stool samples were set up in triplicate and interpreted for each of the following time points; fresh, 24, 48, and 72 hours. The lowest repeatable and reliable quantity of blood detected in the stool at all time points was 50 µl of blood. However, as little as 2 µl of blood was detected in all control samples at fresh, and 24 hours.

A minimum of 6 grams or 0.2 ounces of stool should be collected to detect 50 µl of blood in a stool sample. Additionally, results are repeatable when FOB tests are interpreted as fresh, 24, 48, and 72 hours post set-up. FOB testing is a fast non-invasive diagnostic tool to screen for low levels of blood in the stool of cats.

Disclosures

No disclosures to report.