Fecal occult albumin or hemoglobin from any source, internal or external, will produce a positive FBT result. As a result, practitioners should take care to ensure that blood components are not introduced into the GI tract from external sources prior to using the FBT.
In order to avoid positive results that are not related to the digestive tract, do not use the FBT in the following situations:
Even a small amount of bleeding caused by floating a horse’s teeth, or any lesions around the horse’s mouth, can lead to a positive FBT result. You should avoid using the FBT for 3 days following dental work and be sure that the horse’s mouth and gums are free of lacerations or sores.
With a Horse Prone to Exercise-Induced Pulmonary Hemorrhage
Exercise-induced pulmonary hemorrhaging (EIPH) is most frequently reported in competition horses, presenting as blood in the airways 30-90 minutes after exercise. EIPH is likely to contribute towards a positive FBT from ingested blood, so the clinical history and an awareness of the horse’s competitive activities is imperative.
Regardless, it is always wise to avoid testing within 24 hours of racing or strenuous activity to avoid a false-positive for GI conditions.
During Mare Ovulation
Avoid testing a mare during ovulation, or on/around day five of a typical estrous cycle. Since the follicle in the mare normally fills with blood after ovulation, this blood can potentially interfere with the results of the FBT. Be sure to ask the horse owner when the mare was last in season. When testing during the breeding season ensure that this takes place during diestrus.
After Invasive Procedures or Surgery
Any type of invasive procedure, from routine endoscopy, biopsy, or rectal exam to GI tract surgery, can cause bleeding within, or the introduction of blood into, the digestive tract. This blood would very likely be detected by the FBT leading to a positive result. Gathering recent medical history prior to performing the test is essential.
Remember that the test is sensitive to any equine blood in the feces, whether it has originated from the GI tract or from external sources.
When used properly under the appropriate conditions, the SUCCEED Equine Fecal Blood Test is a powerful veterinary aid, enabling rapid, cost-effective and non-invasive differential diagnosis of GI tract disorders.