Case Report: Overlap syndrome with concurrent polymyositis, masticatory myositis, and lymphocytic thyroiditis in a dog

Case presentationA 4-year-old spayed female mixed breed dog presented for chronic upper airway noises and dysphagia. The dog presented for inspiratory stridor and expiratory stertor. Serum creatine kinase activity was 3,296 IU/L, and cholesterol and triglyceride levels were elevated at 353 mg/dL and 201 mg/dL, respectively. In-house thyroxine levels were below the reference range, prompting the submission of a comprehensive thyroid profile to an outside reference laboratory. Head and cervical CT