Steroid-responsive, cervical, pyogranulomatous pachymeningitis in a dog

Syndromes of steroid-responsive meningitis have been described in the dog and typically are characterized by neutrophilic pleocytosis and an elevated protein concentration of the cerebrospinal fluid. In a minority of cases, histopathology has demonstrated suppurative leptomeningeal (i.e., arachnoid and pia) inflammation. A case of compressive, cervical, pyogranulomatous inflammation of undetermined cause affecting the dura mater (i.e., pachymeningitis), accompanied by fever and hyperpathia, is presented. The pachymeningitis ultimately regressed with long-term immunosuppressive therapy. This case shares features with hypertrophic spinal pachymeningitis of humans, an uncommon, frequently idiopathic, chronic inflammatory disorder causing dural hypertrophy, radiculopathy, and spinal cord compression.