Invasive Squamous Cell Carcinoma of the Larynx in a Dog.

Squamous cell carcinoma (SCC) is a malignant epithelial neoplasm commonly affecting the skin and oral cavity of dogs, whereas laryngeal involvement is considered rare. Neoplasms arising in the larynx may cause severe upper airway obstruction and present diagnostic and therapeutic challenges due to the anatomical and functional constraints of this region. An 11-year-old neutered male mixed-breed dog was evaluated for a one-month history of progressive upper airway obstruction characterized by dyspnea, tachypnea, and dysphagia. Clinical examination revealed a solitary mass protruding into the laryngeal lumen in the arytenoid region. Surgical excision was performed, and intraoperative frozen section evaluation indicated compromised surgical margins. Definitive histopathology confirmed an invasive SCC. Adjunct electrochemotherapy was applied following identification of compromised surgical margins, and the dog showed favorable short-term clinical recovery following surgery. No evidence of recurrence or metastasis was observed during a three-month follow-up period. This case highlights the clinical relevance of laryngeal SCC in dogs and emphasizes the importance of thorough clinical examination and early detection, as well as the integration of clinical evaluation, histopathology, and intraoperative margin assessment in the management of upper airway neoplasms. The combined use of surgical excision, frozen section analysis, and adjunct electrochemotherapy may be considered a potential therapeutic approach in anatomically constrained regions where complete tumor removal is limited.