Plasma urea:creatinine ratio as a biomarker of gastrointestinal bleeding in dogs with anaemia.

Background: Gastrointestinal bleeding is a cause of anaemia in dogs. A reliable, non-invasive biomarker to differentiate gastrointestinal bleeding from other causes of anaemia would be advantageous to direct clinical decisions in anaemic patients. Plasma urea:creatinine ratio is an accepted biomarker of upper gastrointestinal bleeding in human medicine.