A 48-yr-old captive white rhinoceros (Ceratotherium simum) was euthanized due to old age, pododermatitis, and progressive laminitis of the middle toe of the left fore- and hindlimbs. Severe chronic necrotizing periodontitis and dental loss was diagnosed, although food intake prior to death had not decreased. In addition, extensive ulceration of the tongue was noted. Histologically, squamous cell carcinoma of the tongue was diagnosed with chronic severe ulcerative glossitis. Metastatic lesions were not detected. Clinicians should monitor the oral health of aging rhinoceros due to the occult nature of these lesions.
squamous cell carcinoma