Objectives: To measure intra-operative intestinal wall thickness at a standard compression in dogs and cats receiving intestinal surgery and assess associations with species, bodyweight, and pre-operative ultrasonographic measurements.

Study design: Prospective cohort study

Target population: Animals that would be candidates for a stapled small intestinal anastamosis

Sample population: Client-owned dogs and cats undergoing intestinal surgery (enterotomy or intestinal resection/ anastomosis)

Methods: Animals receiving open surgical abdominal exploration for surgical management of suspected small intestinal obstruction due to foreign body or tumor or for management of septic peritonitis due to small bowel perforation will be enrolled. Animals will be subsequently excluded if following exploration they are found not to require either an enterotomy or intestinal resection/ anastomosis. Information will be recorded on species, breed, bodyweight, age, duration of clinical signs, pre-operative exposure to IV fluid therapy, and previous history of inflammatory bowel disease or diffuse intestinal neoplasia. For animals receiving pre-operative ultrasound as a component of their diagnostic work up, bowel wall thickness will be measured ultrasonographically both orad and aborad to the obstructive lesion or area of suspected perforation. Intra-operatively, the bowel wall thickness will be measured using a precision ratchet thimble micrometer at a compression of 6g/mm2. Measurements will be taken both orad and aborad to the identified lesion, either at the enterectomy margins when a resection and anastomosis is performed, or in the nearest bowel assessed by the surgeon as ‘healthy’ and adjacent to the obstruction site when an enterotomy is performed. Associations between an intra-operatively measured intestinal thickness of <1.5mm and >2.0mm and pre-operative measurements and patient factors will be evaluated. Data is anticipated to enable more appropriate recommendations regarding staple sizing in stapled intestinal resections and anastomoses to be developed.