Clinical features, comparative imaging findings, treatment, and outcome in dogs with discospondylitis: A multi-institutional retrospective study

Abstract

Background: Limited recent data exists regarding discospondylitis in dogs. Hypothesis/Objectives: (i) Describe the signalment, clinical and imaging findings, etiologic agents, treatment, and outcome of dogs with discospondylitis, (ii) determine diagnostic agreement between radiographs, CT, and MRI with regard to the presence of discospondylitis and its location, and (iii) determine risk factors for relapse and progressive neurological deterioration. Animals: Three hundred eighty-six dogs. Methods: Multi-institutional retrospective study. Data extracted from medical records were: signalment, clinical and examination findings, diagnostic results, treatments, complications, and outcome. Potential risk factors were recorded. Breed distribution was compared to a control group. Agreement between imaging modalities was assessed via Cohen's kappa statistic. Other analyses were performed on categorical data, using cross tabulations with chi-squared and Fisher's exact tests. Results: Male dogs were overrepresented (236/386 dogs). L7-S1 (97/386 dogs) was the most common site. Staphylococcus species (23/38 positive blood cultures) were prevalent. There was a fair agreement (κ = 0.22) between radiographs and CT, but a poor agreement (κ = 0.05) between radiographs and MRI with regard to evidence of discospondylitis. There was good agreement between imaging modalities regarding location of disease. Trauma was associated with an increased risk of relapse (P =.01, OR: 9.0, 95% CI: 2.2-37.0). Prior steroid therapy was associated with an increased risk of progressive neurological dysfunction (P =.04, OR: 4.7, 95% CI: 1.2-18.6). Conclusions and Clinical Importance: Radiograph and MRI results could be discrepant in dogs with discospondylitis. Prior trauma and corticosteroids could be associated with relapse and progressive neurological dysfunction, respectively.