Thoracolumbar meningeal fibrosis in pugs

BACKGROUND:Thoracolumbar myelopathies associated with spinal cord and vertebral column lesions, with a similar clinical phenotype, but different underlying etiologies, occur in pugs. OBJECTIVES:To further characterize the clinical and neuropathological characteristics of pugs with longstanding thoracolumbar myelopathy. ANIMALS:Thirty client-owned pure-bred pugs with a history of more than a month of ataxia and paresis of the pelvic limbs, suggesting a myelopathy localized to the thoracolumbar spinal cord, were included in the study. METHODS:Prospective clinicopathological study. Included pugs underwent a complete neurological examination and gross and histopathologic postmortem studies with focus on the spinal cord. Computed tomography (n = 18), magnetic resonance imaging (n = 17), and cerebrospinal fluid analysis (n = 27) were performed before or immediately after death. RESULTS:Twenty male and 10 female pugs had a median age at clinical onset of 84 months (interquartile range, 66-96). Affected pugs presented with a progressive clinical course and 80% were incontinent. There was circumferential meningeal fibrosis with concomitant focal, malacic, destruction of the neuroparenchyma in the thoracolumbar spinal cord in 24/30 pugs. Vertebral lesions accompanied the focal spinal cord lesion, and there was lympho-histiocytic inflammation associated or not to the parenchymal lesion in 43% of the pugs. CONCLUSIONS AND CLINICAL IMPORTANCE:Meningeal fibrosis with associated focal spinal cord destruction and neighboring vertebral column lesions were common findings in pugs with long-standing thoracolumbar myelopathy.