The treatment of comminuted tibial shaft fractures in canine patients is burdened by significant risk which involves bone healing complications, such as delayed bone union. Complications may result from iatrogenic damage to blood vessels during fracture stabilization. To minimize this risk, treatment methods increasingly often rely on the concept of biological osteosynthesis. One of such methods involves the treatment of fractures with the use of new hybrid fixator consisted of an interlocking nail connected with type I external fixator. Connection of the nail with external fixator has been recently developed to maximize treatment efficiency. This manner of stabilization increases bone-fixator construct strength on forces acting in the place of fracture. It also enables fracture fixation with minimal damage of the blood supply of bone fragments. This article describes surgical procedure of stabilization of comminuted tibial bone fractures in four dogs by the use of interlocking nail connected with external fixator type I, discusses and evaluates the results of clinical treatment with the involvement of the said fixator. To control bone consolidation process the radiograms were taken in 6 and 8 week of healing. In all cases, the reviewed methods of clinical treatment were successful in producing bone union after eight week of healing. During the whole period of observations no complication was observed. In all cases the intramedullary nail were left in the medullary canal after the healing process was finished. The fixator supported quick restoration of limb function after treatment.