Horizontal and vertical beam radiographs in vomiting dogs to diagnose mechanical gastrointestinal ileus: A diagnostic imaging comparative study.

Background: The horizontal beam (HB) view has been used in the identification of pneumothorax, pleural effusion, and pneumoperitoneum in small animals. Based on the literature, there were no published data evaluating the utility of HB radiography in vomiting dogs to differentiate between patients with or without mechanical gastrointestinal ileus. Aim: The purpose of this prospective pilot study was to determine the utility of HB radiograph as an additional view in vomiting dogs to differentiate patients with or without mechanical gastrointestinal ileus; and describe if there are any radiographic image characteristics associated with the HB view for patients with mechanical gastrointestinal ileus. Methods: A prospective study was carried out on dogs presented with acute vomiting. For all dogs, four radiographic views [ventrodorsal (VD), right lateral, left lateral, and left-to-right lateral HB in sternal recumbency] of the abdomen and abdominal ultrasound were obtained. If a mechanical ileus was detected ultrasonographically, an exploratory laparotomy or endoscopy was performed, otherwise medical treatment was elected. Results: A total of 22 patients were recruited, 11 diagnosed with mechanical ileus and 11 without mechanical ileus. Three blinded reviewers independently assessed the radiographs in three sets: vertical beam (VB) views, HB view alone, and a combination of both views. No statistical difference was found in the differentiation between patients with or without mechanical gastrointestinal ileus between HB views alone or added to VB views. Conclusion: This study suggests that the HB view in sternal recumbency may be an alternative for patients who are not stable enough to be positioned in lateral or VD recumbency.