Background: In the field of spinal surgery, minimally invasive spine surgery (MISS), including microscopic and endoscopic surgery, offers numerous advantages and is increasingly used in spinal surgery. Among these techniques, the biportal endoscopic spinal surgery (BESS), which is mainly used in humans, is a successful option for disc procedures. Objective: Advancement of MISS in veterinary medicine through the application of BESS technique in a canine thoracic intervertebral disc disease (IVDD) model. Materials and Methods: In the pilot group, three medium-sized canine cadavers were used, while in the main group, the sample size was increased to ten medium-sized canine cadavers. Fluorescently dyed artificial disc material with methylene-blue (FDADM-MB) was injected into the thoracic region (T12-13) of cadavers to simulate the development of an IVDD model. The FDADM-MB was removed at this location using the BESS technique. The BESS technique was first applied to pilot cadavers using a computed tomography (CT)-based measurement method and then applied to the main cadavers. To achieve the removal of the FDADM-MB, specialized equipment is utilized. This equipment includes scopes, sheaths, dilators, detachers, radiofrequency (RF) tools, burrs, probes, and retractors, specifically designed for BESS. Pre- and post-operative CT imaging was conducted to confirm the successful removal of the disc material and assess the surgical window. Results: The implementation of BESS using CT-based measurement methods resulted in the successful removal of FDADM-MB in all dogs, with clear observation of the spinal cord and nerve roots. Mini-hemilaminectomy aimed at removing the accessory process was performed appropriately in all dogs. In two dogs, additional osteotomy was required beyond the initially targeted accessory process. The mean portal insertion angle (PIA) measured by the CT method was 31.00 ± 2.79°, and the mean portal insertion distance (PID) was 32.95 ± 3.05°. The mean size of the surgical window created after osteotomy was 33.06 ± 13.90 mm². The mean volume of injected FDADM-MB was 169.26 ± 30.06 mm³, and the mean remaining FDADM-MB post-surgery was 6.89 ± 1.66% of the initially inserted volume. In the IVDD model using bilateral spinal endoscopy, the mean surgical time was 107.75 ± 8.79 min in the pilot group and 48.34 ± 9.60 min in the main group.Conclusion: In this study, we established a methodology for applying BESS technology in veterinary medicine, making it the first of its kind. The CT-based measurement method employed here is also a novel approach in the field of minimally invasive spine surgery in veterinary science. As a result, FDADM-MB was successfully removed from T12-13.