Endoscopic, biopsy, and histopathologic guidelines for the evaluation of gastrointestinal inflammation in companion animals. WSAVA International Gastrointestinal Standardization Group - Washabau, R J; Day, M J; Willard, M D; Hall, E J; Jergens, A E; Mansell, J; Minami, T; Bilzer, T W (J Vet Intern Med, 2010)