Background: Meningoencephalomyelitis of unknown etiology (MUE) is a common cause of neurologic disease in dogs. A paucity of reports exist describing spinal-only MUE.
Hypothesis/
Objectives: To evaluate the clinical presentation, diagnosis, treatment, and outcomes of dogs with spinal-only MUE.
Animals: Twenty-three client-owned dogs diagnosed with spinal-only MUE between 2005-2023
Methods: Multi-center, retrospective, observational study. Dogs with a spinal cord neurolocalization, increased cerebrospinal fluid nucleated cell count, and MRI ruling out extradural spinal cord compression were included. Patient signalment, clinical signs, neurologic examination, diagnostic results, treatment, and outcome were reported.
Results: Modified Frankel Score on presentation was grade 2 in 11 dogs, grade 3 in 5 dogs, grade 4 in 4 dogs, and grade 5 in 3 dogs. The median ratio comparing length of T2W hyperintensity to length of L2 vertebral body was 5.6 (range 1.6-15.3). All 23 dogs were treated with prednisone (dose 0.7-3.0 mg/kg/day); 18 dogs received additional immunosuppressive medications. Seven dogs (30.4%, 95% CI: 13.2-52.9%) were alive at study completion; 8 dogs (34.8%, 95% CI: 16.4-57.3%) were euthanized, 8 dogs (34.8%, 95% CI: 16.4-57.3%) were lost to follow up. For patients with serial neurologic examinations, 5 had improvement, 9 were unchanged, and 1 had worsening of neurologic grade. At time of study completion, 9 dogs (39.1%, 95% CI: 19.7-61.5%) were euthanized or worsened neurologically.
Conclusions and Clinical Importance: Prognosis for spinal-only MUE is guarded long term.
