Christopher M. Baldwin

Summary Common pathology within the digital flexor tendon sheath (DFTS) includes tearing of the manica flexoria , marginal longitudinal lesions of the deep digital flexor tendon and fetlock canal constriction. These are a frequent cause of lameness in cob‐type breeds where skin thickness can make obtaining diagnostic ultrasound images difficult. Radiographic contrast tenography in the standing patient can be used to identify pathology but provides limited information on the exact lesion configuration. This report describes the use of computed tomographic contrast tenography under general anaesthesia to identify and detail the configuration of intrathecal DFTS pathology in four clinical cases (six limbs) subsequently assessed with DFTS tenoscopy. Computed tomography findings altered surgical planning in two cases, and in all cases computed tomography findings were confirmed by tenoscopy. Computed tomographic contrast tenography correctly predicted all lesions observed during tenoscopy: manica flexoria pathology including laterality (4/4 torn and 2/2 intact), fetlock canal constriction (3/3 limbs), deep digital flexor tendon injury (1/1) and intrathecal adhesions (5/5 limbs). Computed tomographic contrast tenography was a useful pre‐operative imaging modality which aided surgical planning. The technique may be applicable for use in standing computed tomography systems where it would provide the diagnostic benefits listed without the associated risk of prolonging anaesthesia.

Background Mesodiverticular bands (MDBs) are an embryonic remnant of the vitelline artery. Information about the clinical significance of equine MDBs is currently limited. Objectives To report the clinical features, surgical findings and outcomes of horses undergoing exploratory laparotomy where a MDB was identified. Study design Retrospective case series. Methods Case records of horses undergoing exploratory laparotomy for colic over a 14‐year period (2009–2022) were reviewed. MDBs identified at laparotomy were classified as the primary or contributory cause of abdominal pain, or as incidental. Results MDBs were identified in 40/1943 horses (2.1%) and 15 were primary (32.5%), 10 contributory (25%) and 15 incidental (32.5%). Horses with primary MDBs (median 2 years, IQR 1–12) were significantly younger than horses with incidental MDBs (median 8 years, IQR 6–16; P = 0.01). MDBs were more likely to be incidental if located in the mid‐jejunum (5/5) ( P < 0.001) or where a mesenteric pocket was absent (11/15) ( P = 0.01). Primary MDBs caused extra‐mural obstruction due to mesenteric shortening ( n = 4), small intestinal entrapment within the MDB pocket ( n = 5) or in an adjacent mesenteric rent ( n = 4), and volvulus around the MDB ( n = 2), with intestinal resection required in 8/15 cases. For horses with primary MDBs, survival to hospital discharge was 60% overall (9/15) and 75% for horses that stood following anaesthesia (9/12) with 88.9% of cases discharged from hospital (8/9) surviving >1 year. Excision of MDB tissue was not associated with complications but 3/4 non‐incidental MDBs left in situ required relaparotomy to treat MDB‐associated colic. Main limitations Retrospective single centre data. Conclusions Most MDBs in horses undergoing surgical treatment of colic in this population were not incidental. MDB‐associated colic was most commonly classified as strangulating obstruction, but non‐strangulating extra‐mural compression was also identified. Excision of MDB tissue should be undertaken where possible, particularly in non‐incidental cases.