HISTOCHEMICAL AND IMMUNOHISTOCHEMICAL ANALYSIS OF HERNIATED DISC TISSUE SURGICALLY REMOVED FROM DOGS

Introduction: The hernias of intervertebral discs are a common and debilitating disease in dogs usually hesitate in surgery. This study was aimed to score, based on a modified histological grading system, the samples taken in vivo, and associate these with related clinical data. Materials and Methods: Surgery herniated disc material was collected from 29 dogs. The samples were processed and stained by H&E, histochemistry using Gruber, and by immunohistochemistry using FVIII. For all samples, at least 3 months follow up was available. Results: Inflammation was added as a parameter in the grading system and scored 0 when not present and 1 when present. All cases with inflammatory cells showed simultaneously presence of fibrosis, mineralization and neoangeogenesis. The amount of proteoglycans of the extracellular matrix decreased proportionally with the increase of cells chondrocyte proliferation. Discussion and Conclusion: According to the present results, most of the samples were scored as grade 3 in the modified grading system going from grade 1 to 5. This data can be partially explained by the variability of histological material, this being taken in vivo and in most cases consists only of the nucleus pulposus. Separating and applying the scoring for the annulus fibrosus and for the pulpy nucleus, based on the collected material, may give more precise scores.