This study aimed to evaluate the feasibility of percutaneous endoscopic foraminotomy (PEF) for the treatment of intervertebral disc herniation of the thoracolumbar spine in large-breed dogs by comparing it with open hemilaminectomy (OH). Six large-breed canine cadavers were used in the present study. A barium and agarose mixture (BA-gel) simulating intervertebral disc herniation was injected into the spinal canal at two intervertebral spaces (T12-T13, L2-L3) of the thoracolumbar spine in each cadaver. PEF and OH were randomly allocated to the sites in each cadaver. Computed tomography was performed pre- and postoperatively. The incision length, vertebral window size, procedure time, and amount of simulated disc material removed were recorded to compare PEF and OH. Both procedures clearly exposed the simulated disc material and spinal cord. The size of the incision and vertebral window created after PEF was much smaller than those after OH. The surgical duration of PEF was longer than that of OH. However, no significant difference (P>0.05) was observed in the amount of BA-gel removed between PEF and OH. Thus, PEF could be used as an effective surgical option for intervertebral disc herniation of the thoracolumbar region in large-breed dogs in that it could lead to less tissue damage as well as sufficient removal of the simulated disc material.