Outcomes of 87 small-breed dogs surgically treated for Chiari-like malformation and syringomyelia

Abstract

Objective: To report the outcomes of titanium mesh (TM) cranioplasty without polymethylmethacrylate (PMMA), incorporating a deliberate gap between the foramen magnum decompression (FMD) surface and the TM, in small-breed dogs with Chiari-like malformation and syringomyelia (CM/SM). Study design: Retrospective clinical study. Animals: A total of 87 client-owned small-breed dogs diagnosed with CM/SM by magnetic resonance imaging, all presenting with neurologic deficits. Methods: All dogs underwent modified FMD. A gap was preserved between the FMD surface and the TM to facilitate tissue integration and reduce postoperative compressive forces. Clinical status was assessed based on neurologic improvement, medication dependency, and need for revision surgery. Results: Surgical decompression with the modified TM technique resulted in sustained clinical improvement in most dogs. A total of 76 dogs (87%, 76/87) showed long-term improvement, and no revision surgeries were required during a median follow-up of 35 months (range: 27–73 months). Follow-up evaluation comprised postoperative computed tomography (CT) imaging at 6 months, as well as structured telephone interviews with owners to monitor clinical status. Only a small subset of dogs (13%, 11/87) required continued medication after surgery due to recurrence of signs. Conclusion: Retrospective analysis showed that the modified TM technique, using a deliberate gap, was safe and effective in small-breed dogs with CM/SM, successfully preserving the decompression space and maintaining long-term neurologic stability. Clinical relevance: The modified TM technique approach achieves durable neurologic improvement and minimizes long-term complications in small-breed dogs, demonstrating practical utility in managing this clinically challenging population.