Diagnostic Imaging of Gastrointestinal Tumours in Dogs and Cats: A Review

Gastrointestinal tract tumours in dogs and cats are characterized by non-specific clinical presentation and laboratory abnormalities, but require fast identification, characterization and staging. Imaging techniques play a key role in the diagnostic process of these diseases in routine veterinary practice. Survey and contrast radiography may indicate primary or secondary signs of gastric or intestinal neoplasia such as a wall mass, functional alterations and stenosis points, but they have low sensibility and limited diagnostic value. Ultrasound allows to perform a detailed study of gastrointestinal wall's layers and thickness and adjacent organs but requires adequate acoustic windows and expert operators. Computed tomography is a reference technique both in human and veterinary oncology for the identification of primary neoplasms and for metastases searching thanks to the possibility to scan the whole body and the use of intravenous iodinated contrast medium for vascular assessment. Specific intraluminal distension techniques such as Helical-Hydro Computed Tomography and Computed Tomography Colonography can improve respectively stomach and colon associated masses. To date, Endoscopic Ultrasonography and Magnetic Resonance, despite their proven value in human medicine, lack of literatures that support their usefulness in the diagnosis and staging of gastrointestinal neoplasms in veterinary medicine and are not widely used in these pathologies. The purpose of this work is to review the literature on imaging modalities applied in gastrointestinal tumours diagnosis in dogs and cats, highlighting advantages and limitations of each technique in order to choose the proper imaging procedure in everyday clinical practice.