Thoracic vertebral canal stenosis in cats: clinical features, diagnostic imaging findings, treatment and outcome.

Abstract

The aim of this study was to describe the clinical features, diagnostic imaging findings, treatment and outcome in cats with thoracic vertebral canal stenosis (TVCS). Medical records and imaging studies of cats with TVCS were retrospectively reviewed. Outcome was acquired from patient records and from owners or referring veterinary surgeons via a telephone questionnaire. For each case, breed-, age- and sex-matched controls were identified with CT imaging of the thoracic vertebral column. For each cat, vertebral canal height was determined at three levels for each thoracic vertebra. Vertebral canal heights were compared between control cats of different breeds and between affected and control cats of the same breed. Nine TVCS cases were included. British Shorthairs and male neutered cats were over-represented (P <0.05). Median age at presentation was 9 years. All cats were presented for a chronic, progressive, painful, ambulatory, T3-L3 myelopathy. Five cats were treated conservatively, three surgically and one was euthanased. Two cats treated surgically demonstrated improvement of clinical signs and one demonstrated initial improvement followed by deterioration. Of the conservatively treated cats, three deteriorated and two improved. Compared with controls, affected cats had a lower vertebral canal height at multiple thoracic vertebral levels, being most prominent for British Shorthairs and domestic shorthairs (P <0.05). Unaffected British Shorthairs had a lower thoracic vertebral canal height at multiple levels than control domestic shorthairs (P <0.05). TVCS should be considered a differential diagnosis in middle-aged to older cats presenting with a chronic, progressive, painful, T3-L3 myelopathy. The predisposition of British Shorthairs could be explained by a narrower vertebral canal in this breed.