To determine the influence of breed (cob [CB] and non-cob [NC]), obturator type and surgical experience on the number of attempts, time taken and iatrogenic damage (ID) created when entering the digital flexor tendon sheath (DFTS) tenoscopically. Prospective experimental cadaveric study. A total of 104 cadaver limbs. An equal number of randomly selected CB and NC limbs were operated using a conical obturator (OB) or a switching stick (SS) by one boarded (BS) and one resident surgeon (RS). Skin measurements, number of attempts and time taken to enter the DFTS were recorded. The DFTS was endoscopically examined and then dissected to record ID and cumulative ID calculated. Mean CB skin thickness (8.4 mm) was nearly twice that of NC limbs (4.5 mm) (p < .001). Mean DFTS entry took longer in CB limbs (133 s) compared to NC limbs (112 s) (p = .02). BS mean entry time in CB limbs was 115 s compared to 46 s in NC limbs (p < .001). Cumulative ID was greater in CB limbs (25 of 52 limbs with ID) compared to NC limbs (14 of 52 limbs with ID) (p = .04). No difference was noted between obturators. Surgical experience reduced attempts and time entering the DFTS. Surgeons take longer to enter DFTS in CB limbs and more cumulative ID is created, regardless of obturator type used. Skin thickness is a major determinant of time taken to enter the DFTS and increases the risk of ID. Awareness of the challenges in CB limbs is important.