Lumbar intervertebral foraminal disc extrusion in a cat

Case summary A 10-year-old domestic longhair cat was presented for investigations into a 4-day history of acute-onset lethargy, hyporexia and right pelvic limb lameness. Based upon the neurological examination, a right femoral nerve localisation was suspected. Pelvic radiographs identified a dorsally displaced L5-L6 intervertebral disc, with subsequent MRI suggestive of a right L5-L6 neuritis secondary foraminal intervertebral disc extrusion. Medical management, consisting of rest and analgesia, resulted in near-complete resolution of clinical signs in 37 days. Relevance and novel information To our knowledge, this is the first report of a lumbar foraminal intervertebral disc extrusion in a cat and should be considered on the differential list for acute-onset pelvic limb lameness in the absence of neurological deficits.