A 24 year old thoroughbred gelding presented to Cornell University’s Equine and Farm Animal Hospital for a possible tongue laceration. He had a history of weight loss, hypersalivation, quidding, and dysphagia. The patient had several chronic medical conditions including Cushing’s disease, chronic uveitis, and Equine Odontoclastic Tooth Resorption and Hypercementosis (EOTRH). Five days prior to presentation the patient’s teeth were floated. The referring veterinarian diagnosed a presumptive tongue laceration and started the patient on oral trimethoprim sulfa, phenylbutazone, and gastrogard. Due to lack of improvement the patient was referred to Cornell for further evaluation.

On presentation the patient was quiet, alert, and responsive, but underweight. Vital parameters were all within normal limits. The left eye was atrophied and avisual due to previous uveitis. Mild submandibular lymphadenopathy was palpated. The patient was offered a small amount of hay and was observed to prehend and chew normally but when swallowing he tucked and shook his head and then dropped the hay. An oral exam revealed a large ulcerated lesion on the right caudolateral aspect of the tongue. No significant abnormalities were found on endoscopic exam of his nasopharynx or guttural pouches. The problem list consisted of the ulcerative lingual lesion and associated submandibular lymphadenopathy, hypersalivation, dysphagia, quidding, and weight loss.

Differential diagnoses included lingual foreign body, abscess, neoplasia, trauma, or a primary infection such as actinobacillus lignieresii (wooden tongue). Secondary glossitis was considered likely with a foreign body, neoplasia, or trauma. Radiograph and ultrasound examinations were negative for a foreign body or abscess. Fine needle aspirates and biopsy samples were obtained under short duration anesthesia and were definitive for squamous cell carcinoma. Due to the location and extent of disease surgical resection was impossible and humane euthanasia was recommended.

This case report will discuss the presentation, possible etiologies, diagnosis, treatment, and prognosis of both equine squamous cell carcinoma and EOTRH.