Surgical stabilisation of hiatal hernia and gastroesophageal reflux associated with idiopathic inflammatory polymyopathy in a Wire Fox Terrier

A one-and-a-half-year-old male Wire Fox Terrier weighing 3 kg presented with continuous drooling and vomiting. Its body condition score was 3/9, and severe atrophy of the temporal/masticatory muscle, trismus, and enophthalmos was observed on physical examination. The radiographic examination and fluoroscopic oesophagography revealed a type 1 hiatal hernia with gastroesophageal reflux. The serology tests revealed increased muscle enzyme activities. The antibody tests for acetylcholine receptor, type 2M fibre, and infectious agents were negative. A conventional surgical treatment was performed, and a thickened, stretched, and flaccid diaphragmatic muscle and an extended inelastic oesophageal hiatus were observed. On the histological examination of the diaphragmatic muscle, a diffuse histiocytic myositis was confirmed. Although the postoperative gastroesophageal reflux totally disappeared, the oesophageal motility and clinical signs did not improve significantly. Medical treatment with immunosuppressive agents was attempted and was effective in alleviating the clinical signs and abnormal oesophageal motility. The health condition of the dog was adequately maintained in the 12-month monitoring period. These findings suggest that, although the medical and surgical treatment have different therapeutic effects, they should be considered simultaneously for the management of a hiatal hernia associated with polymyopathy in dogs.