This patient presented with acute signs indicating vestibular disease, and mass lesions were discovered during the work-up. The vestibular signs were variable but suggested a possible central origin. However, MRI of the head and neck did not reveal a central lesion. An ear canal mass with inflammation and presumed ruptured eardrum may have caused the vestibular signs. The cause of the vomiting was not determined. A thyroid tumor was discovered and diagnosed as a carcinoma. In dogs, the vast majority of thyroid tumors are malignant. They do not usually secrete hormone but may cause a mild hyperthyroidism. Imaging is important, because the tumors are locally invasive and may involve other vital structures in the neck, making surgery higher risk. The tumors may also metastasize to the lungs and occasionally to the heart. Surgical treatment with radiation therapy is recommended, but long-term prognosis is guarded. Pre-existing, chronic conditions in geriatric patients may affect prognosis and advisability of some treatments.
Links to sections in The Manual:
Physical and Neurologic Examinations
Tumors of the Ear Canal
Thyroid C-cell Tumors
References
Castillo V, Pessina P, Hall P, Cabrera Blatter MF, Miceli D, Soler Arias E, Vidal P. Post-surgical treatment of thyroid carcinoma in dogs with retinoic acid 9 cis improves patient outcome. Open Vet J. 2016; 6(1): 6–14. doi: 10.4314/ovj.v6i1.2
Campos M, Ducatelle R, Rutteman G, Koositra HS, Duchateau L, de Rooster H, Peremans K, Daminet S. Clinical, Pathologic, and Immunohistochemical Prognostic Factors in Dogs with Thryoid Carcinoma. J Vet Intern Med. 2014 Nov-Dec; 28(6):1805-1913. doi: 10.1111/jvim.12436