Medical records for dogs treated with tibial plateau leveling osteotomy (TPLO) using Arthrex 3.5 mm self-tapping screws (STS) were evaluated to determine the incidence rate of transcortical tibial fractures (TCTF) and development of complications. Retrospective case report. A total of 78 dogs. Dogs that underwent a TPLO performed from March 2022 to August 2023 were reviewed. Postoperative TPLO radiographs were examined for evidence of a TCTF with Arthrex 3.5 mm STS. Records were reviewed for complications up to 14 weeks after surgery. Evidence of a TCTF was found in 42% of cases (33 of 78) and 14% (36 of 250) of STS screws distal to the osteotomy. TCTFs were only identified distal to the osteotomy. Three dogs had radiographic evidence of more than one TCTF. Of the dogs with radiographic TCTF, 6% of patients (2 of 33) developed a major complication that required surgical stabilization of a tibial fracture associated with screw angulation relative to the plate. Use of Arthrex 3.5 mm STS for TPLO is associated with risk of TCTF. TCTF can compromise the structural properties of the tibia and cause complete tibial fracture requiring major revision surgery. Development of TCTF after use of STS for TPLO has been recognized, in contrast to use of non-self-tapping screws, and was considered a benign complication. Our findings suggest TCTF associated with Arthrex 3.5 mm STS use in TPLO can contribute to major complications after surgery, including complete tibial fracture, particularly if screws are not placed perpendicular to the plate.