ORIGINAL ARTICLE A vascularized preputial free flap for labial reconstruction in a dog Chi-Hsin Liu, DVM, MS | Lih-Seng Yeh, DVM, PhD Institute of Veterinary Clinical Sciences, School of Veterinary Medicine and Veterinary Teaching Hospital, National Taiwan University, Taipei, Taiwan, ROC Correspondence Lih-Seng Yeh, Institute of Veterinary Clinical Sciences, School of Veterinary Medicine, National Taiwan University, Number 1, Section 4, Roosevelt Road, Taipei 10617, Taiwan, ROC. Email: lsyeh@ntu.edu.tw Abstract Objective: To describe the clinical application of a vascularized preputial free flap in the reconstruction of a large facial-labial defect. Study design: Case report. Animals: An adult neutered male mongrel dog with a large left facial-labial defect. Methods: A preputial free flap was created by elevating the cranial part of the pre- puce, using the ipsilateral caudal superficial epigastric vessels as a vascular pedicle. The flap was transferred to the facial-labial defect and the donor vessels anastomosed to the sublingual artery and vein, using standard microvascular technique. Results: The free flap survived, leading to good cosmetic and functional outcomes. No major complications were encountered at either the donor or recipient sites after 2 years of follow-up. Conclusion: Vascularized preputial free flaps can be used to manage composite facial and oral cavity defects involving large areas of skin and mucosa. 1 | INTRODUCTION Soft tissue defects involving the lips, cheek, and oral cavity may result from a congenital disorder, wide tumor resection, infection, or trauma in small animals. Such defects create unique challenges in terms of restoring function of the oral cavity with acceptable cosmesis. 1 Plastic reconstruction of oral defects may involve local tissue advancement, transposi- tion flaps, and geometric closure techniques. 2-4 In larger defects, especially those involving gingival mucosa, local skin flaps may not result in adequate and functional closure. A preputial free flap was described for the reconstruction of oral and oropharyngeal defects in human medicine in 1998. 5 This flap offers several advantages as it is thin and pliable, and provide a large surface area with a long vascular pedi- cle. 6 In addition, human patients did not experience morbid- ity associated with this circumcision. 5 To the authors’ knowledge, the use of the prepuce in veterinary surgery has been limited to an indirect flap for urethral reconstruction in dogs with hypospadias. 7-9 Our report is the first to describe the repair of a large facial-labial defect with a vascularized preputial free flap in the dog. 2 | CLINICAL REPORT A neutered male adult mongrel dog was referred for evalu- ation of a large facial-labial defect. The defect was noted when the dog was rescued by a charity group 6 months ear- lier. The etiology of the defect was unknown. The scale of soft tissue trauma included a skin-mucosa defect extending from the first upper premolar to the first upper molar on the left side of his face (Figure 1). The gingival tissue over the left upper gum was healed with the remaining facial skin margin, where the buccal mucosa of the left side of the face was absent. The teeth and attached gingiva over the gum were exposed from the labial defect, leading to constant mouth drying and inflammation. The extensive scar formation also greatly reduced the range of motion of the mandible. Veterinary Surgery. 2017;1–4. wileyonlinelibrary.com/journal/vsu V C 2017 The American College of Veterinary Surgeons | 1 Received: 17 August 2016 | Accepted: 21 March 2017 DOI: 10.1111/vsu.12694