An Air Force veterinarian consulted with an Air Force endodontist concerning the fractured canine in a German shepherd sentry dog. Exposure of the pulp was evident and root canal therapy was initiated; general anesthesia was used. Problems were encountered in preparation of the canal because of its length. Conventional endodontic therapy was completed at a second appointment after custom instruments and filling materials were designed and constructed to compensate for the length of the canal. Successful conventional endodontic therapy was performed on a valuable military dog. Surgical intervention was avoided by designing custom-made materials. Endodontic principles were successfully applied to serve as definitive treatment in veterinary medicine.