Lumbosacral pain and radiculopathy in dogs are distinct but frequently co-occurring conditions that require integration of physical examination, the LSPain Scale, and MRI to differentiate and direct treatment.

Differentiating Lumbosacral Pain from Radiculopathy

Lumbosacral pain is identified by behavioural responses to palpation of the lumbosacral region, scored using the LSPain Scale (0 = no pain to 3 = severe pain). This 4-point ordinal instrument has demonstrated strong convergent and discriminant validity, inter- and intra-rater reliability, and responsiveness to treatment across experience levels, making it the recommended standardised tool for both initial assessment and monitoring.Frontiers in Ve… Pain responses on lumbosacral palpation overlap substantially with hip conditions, so physical examination alone is insufficient to localise the pain source.Animals

Radiculopathy is distinguished by nerve root signs: ipsilateral hind limb lameness, proprioceptive deficits, and limb-specific neurological changes. Unilateral lumbosacral MRI findings are associated with clinical signs on the ipsilateral hind limb in 85% of dogs.Veterinary Surg… Radiculopathy affecting the L7 spinal nerve is the strongest predictor of lumbosacral pain specifically, while intervertebral disc (IVD) extrusion is the primary pathology associated with lumbar pain.Animals On MRI, L7 radiculopathy manifests as nerve root enlargement, nerve root hyperintensity relative to surrounding connective tissue on dorsal oblique gradient echo short time inversion recovery sequences, and changes in nerve root shape, size, or position on transverse T1-weighted sequences.Veterinary Surg…

Loss of foraminal fat signal on MRI is the key screening finding for foraminal stenosis and radiculopathy. Of 480 neuroforamina evaluated, loss of foraminal fat signal was present in 364, of which 87.9% also showed concurrent nerve root changes.Veterinary Surg… Foraminal stenosis, IVD bulging, and IVD protrusion are all significantly associated with lumbosacral pain on multivariable analysis.Animals Importantly, some dogs with MRI-confirmed pathology show no pain, and some painful dogs have no detectable MRI abnormality — imaging must always be interpreted within the clinical context.Animals

The differential diagnosis for lumbosacral pain must include degenerative lumbosacral stenosis (DLSS), discospondylitis, neoplasia, and — rarely — infectious sacroiliitis. DLSS is the most common cause of caudal lumbar back pain in middle to large breed dogs.BMC Veterinary… Discospondylitis originates most commonly from haematogenous spread of urogenital infection and can cause secondary DLSS through vertebral instability and bone proliferation.BMC Veterinary… Infectious sacroiliitis is rare, with clinical presentation nearly indistinguishable from DLSS, discospondylitis, and hip dysplasia; diagnosis is one of exclusion based on imaging and culture results.Journal of the… The degree of cauda equina compression does not reliably correlate with severity of clinical signs, reinforcing the need for multimodal assessment.American Journa…

Treatment

Conservative management of DLSS is first-line for dogs without urinary or faecal incontinence and without proprioceptive deficits. This includes non-steroidal anti-inflammatory drugs, opioid analgesics, body weight reduction, adjusted exercise, and physiotherapy.BMC Veterinary… Epidural infiltration with methylprednisolone acetate is an established medical option within this population, provided discospondylitis is absent.BMC Veterinary… Discospondylitis requires long-term antibiotic therapy as the primary treatment.BMC Veterinary…

For chronic lumbosacral pain with radiculopathy, interventional pain management using combined ultrasound- and fluoroscopy-guided foraminal and epidural corticosteroid and local anaesthetic injections is an emerging approach. A transforaminal technique targeting the L7 foramen achieves perineural epidural staining of L7 in 90% of injections, with transforaminal epidural spread in 80%, subarachnoid spread in 50–60%, and vascular uptake in only 10–20% of injections in cadaveric models.Animals In dogs with chronic lumbosacral pain treated with this approach, pain severity and quality of life (QoL) improved significantly over time in both injection-only and injection-plus-pulsed radiofrequency (PRF) groups.Frontiers in Ve…

Adding PRF at the L7 dorsal root ganglion (DRG) to foraminal and epidural injections produces significantly greater QoL improvement than injections alone. Outcomes were followed for up to 24 months following a single procedure.Frontiers in Ve… A cadaveric feasibility study for PRF electrode placement adjacent to the L7 DRG using combined ultrasound and fluoroscopy guidance achieved a mean electrode-to-DRG distance of 1.96 ± 1.07 mm, confirming precise positioning is achievable.Animals Clinical efficacy and safety data in live patients are not yet established for the PRF technique.Animals

Surgical decompression via dorsal laminectomy or foraminotomy, with or without partial discectomy and facetectomy, is indicated for dogs with progressive neurological deficits. Short-term improvement occurs in 78–93% of surgically treated dogs, but clinical signs recur in 17–38% long-term.BMC Veterinary… Propulsive force of the pelvic limbs is not fully restored after decompressive surgery on force plate analysis.BMC Veterinary… Facetectomy may worsen lumbosacral instability in some patients, contributing to recurrence.BMC Veterinary…

Would you like guidance on the specific corticosteroid and local anaesthetic agents and doses used for lumbosacral foraminal injections in dogs?