Case report: Incidental finding of a perforating wooden foreign body in the jejunum during surgical treatment of colic in a horse: use of intraoperative infrared thermography

Background: Equine gastrointestinal tract perforation by a foreign body is a rare cause of colic. Assessment of intestinal viability during exploratory laparotomy is crucial and is usually performed using subjective parameters (color, motility, pulse). Infrared thermography (IRT) offers an objective, noninvasive method for assessing tissue surface temperature in real time, as it correlates with local blood perfusion. Case presentation: In this case, a 13-year-old Italian Saddle mare was admitted with a 24-h history of acute, progressive abdominal pain unresponsive to medical therapy. Clinical examination revealed severe discomfort, systemic compromise (HR: 53 bpm, CRT > 3 s), marked leukocytosis (16,600 cells/mm3), hyperproteinemia (8 g/dL), and severe hyperlactatemia (15 mmol/L). Transabdominal ultrasound confirmed small intestinal distention. Emergency exploratory laparotomy revealed a 10cm solid, irregular mass in the jejunum, causing obstruction and localized perforation. Intraoperative infrared thermography (FLIR ThermaCam E8) was used at three time points (T0: exteriorization, T1: margin selection, T2: pre-repositioning) to monitor surface temperature distributions. At T0, a distinct thermal gradient (Delta T = 1.9 ◦C) was detected between the viable intestinal segments (mean T = 35.1 ◦C) and the affected ischemic area (mean T = 33.2 ◦C). Based on the clinical examination and findings, a segmental enterectomy with end-to-end anastomosis was performed. Post-resection mapping (T2) confirmed equal perfusion of both stumps with a difference between measurements of: Delta T = 0.1 ◦C. Dissection of the resected mass revealed a wooden stick. The mare recovered uneventfully and was discharged 10 days after surgery. Conclusion: This case demonstrates that foreign body-associated intestinal perforation should be considered among the differential diagnosis of horses presenting with severe small intestinal colic. Furthermore, intraoperative infrared thermography proved to be an adjunctive method for real-time quantification of surface temperatures in the examined stumps, providing an objective assessment of surface temperature patterns to complement visual inspection during tissue evaluation.