Evaluation of BUN/creatinine ratio and video capsule endoscopy in diagnosing gastrointestinal bleeding in dogs

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Stiller, Jenny

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University of Guelph


Gastrointestinal bleeding (GIB) is a common cause for presentation to veterinary hospitals in dogs. While BUN/creatinine ratio and video capsule endoscopy (VCE) are used in people to aid in the diagnostic challenge of GIB, the literature on these diagnostics is scarce in veterinary medicine. Consequently, the objectives of this thesis were the following: assess the usefulness of BUN/creatinine ratio to predict occult GIB and to distinguish upper from lower GIB in dogs, and assess diagnostic yield, quality of visualization, and complications of VCE in dogs with overt or suspected occult GIB and to identify possible risk factors associated with incomplete VCE study. In the first study, 89 dogs with GIB and 65 clinically healthy dogs were enrolled retro- and prospectively. Gastrointestinal bleeders were classified depending on the presence of overt (n=65) or occult (n=24) GIB and localization of bleeding lesions (37 upper GI tract, 13 lower GI tract, 8 both). Results identified that BUN/creatinine ratio could not predict occult GIB nor distinguish upper from lower GIB. Dogs with higher hemoglobin and hematocrit had significantly lower odds of having occult GIB than being clinically healthy (P < 0.0001). In the second study, 40 dogs were examined by VCE because of suspected occult (n=27) or overt (n=13) GIB. The capsules were administered orally (n=29) or deployed endoscopically (n=11). In 24 of 39 recordings, bleeding lesion(s) were identified. Quality of visualization was poor to limited in the stomach and colon, and adequate to good in the small intestine. The most common complication was an incomplete study noted in 15/39 studies, particularly when capsules were administered orally (13/28). Risk factors for incomplete studies after oral administration included administration of simethicone or opioids, chronic enteropathy, and capsule gastric transit time > 6 hours. In conclusion, BUN/creatinine ratio was not a useful marker of occult GIB and had poor discriminatory ability to distinguish upper from lower GIB. VCE could be used to diagnose bleeding lesions in the entire GI tract of dogs. Diagnostic yield was decreased by poor visibility of the GI mucosa and incomplete studies. The latter was the most common complication in our study.



Gastroenterology, Canine, GI hemorrhage, GI bleeding, BUN creatinine ratio, Urea creatinine ratio, ALICAM, Enteropathy, Simethicone, Incomplete study, Video capsule endoscopy