Occult tethered cord syndrome in the canine: Microsurgical resection of the filum terminale

Abstract

A 5-month-old male Spinone Italiano dog presented with progressive urinary incontinence, pollakiuria, hind limb weakness and the impression of lumbosacral pain not responsive to medical treatment. Based on non-diagnostic bladder structure, urinalysis, and no obvious spinal pathology on lumbosacral MRI, the constellation of symptoms was suspicious for occult tethered cord syndrome. A standard L7-S1 laminectomy was performed to detether the filum terminale. By 5 weeks post-op the dog’s hind limb weakness and lumbosacral pain had resolved, and urinary incontinence was markedly improved. At 10 months post-op the owner reported continued improvement of the urinary incontinence and improved behavior to suggest significant pain relief. In a young dog with progressive urinary incontinence, orthopedic or neurological dysfunction with no structural neurological or urogenital abnormalities, a hypothesis of occult tethered cord syndrome should be discussed. If the condition is progressive and no medical response is obtained, a detethering of the filum terminale is a viable option.