Diagnosis of erythema multiforme associated with thymoma in a dog and treated with thymectomy.

A 7 yr old Labrador retriever initially presented for severe halitosis, mild ptylism, and depigmentation of the nasal planum. Erythema multiforme was diagnosed based on clinical signs and dermatopathology. Treatment was initiated but the condition did not resolve. Six months later, the dog was diagnosed with a mediastinal mass. Trucut biopsy was performed and histopathologic diagnosis was consistent with a thymoma. A median sternotomy was performed, the thymoma was excised, and the dog recovered well. Four months postoperatively, there were no longer any obvious erythema multiforme lesions and the skin condition was controlled without medication. Erythema multiforme may be a paraneoplastic disorder associated with thymoma in the dog, similar to thymoma-associated exfoliative dermatitis in the cat. Clinical signs of erythema multiforme may warrant performing thoracic radiographs or thoracic CT to rule out thymoma as an underlying cause.

A modified ventral approach to the atlantoaxial junction in the dog.

OBJECTIVE: To describe and evaluate a surgical technique using a modified ventral approach for stabilization of the atlantoaxial (AA) junction in dogs with AA subluxation. STUDY DESIGN: Retrospective study. ANIMALS: Dogs (n=5) with AA subluxation. METHODS: Medical records (2000-2006) of 5 dogs with AA treated by stabilization via a right parasagittal approach were reviewed and outcome assessed by clinical examination and phone interviews with owners. RESULTS: The AA joint was clearly visualized and fixation devices were placed in all dogs. A right parasagittal approach provided excellent access to the AA junction and avoided dissection around the thyroid gland, trachea, and recurrent laryngeal nerve. Recovery was considered good to excellent by owners, and dogs returned to good function. CONCLUSIONS: A right parasagittal approach to the AA junction provides improved exposure and allows for surgical stabilization with minimal complications. CLINICAL RELEVANCE: In dogs that require surgical stabilization of the AA joint, a right parasagittal approach should be considered. This approach offers advantages over the standard ventral median approach by improved surgical exposure, less dissection, and provides protection of vital structures during insertion of fixation devices used for ventral AA stabilization.