A Standardized Magnification-Assisted Microsurgical Approach for Canine Spinal Arachnoid Diverticulum: Retrospective Short-Term Outcomes in 11 Dogs

Spinal arachnoid diverticulum is a fluid-filled dilation within the subarachnoid space that can result in compressive myelopathy, prompting investigation into optimal surgical management and outcomes. This retrospective study reviewed clinical records of dogs treated surgically between January 2021 and July 2025, including 11 cases that met the criteria of chronic progressive para- or tetraparesis, MRI-confirmed diagnosis, and use of a standardized surgical technique. All dogs underwent dorsal laminectomy followed by durotomy, durectomy, and microsurgical dissection of adhesions performed by the same surgeon, with optical magnification and specialized instruments to ensure consistency. The condition was more common in males, with French Bulldogs overrepresented (n = 6); lesions were thoracolumbar in small breeds and cervical in the single large-breed dog. Short-term outcomes, assessed one month postoperatively, showed neurological improvement in all but one dog. These findings suggest that the described microsurgical approach is feasible and associated with favorable short-term neurological recovery in most cases. However, the absence of long-term follow-up limits definitive conclusions, and further studies are needed to evaluate sustained outcomes.