Electrodiagnostic findings in dogs with apparently painful lumbosacral foraminal stenosis.

Background: Development of management strategies for lumbosacral stenosis in dogs is hampered by the lack of objective diagnostic criteria and outcome measures.

Objective: To explore the suitability of electrodiagnostic tests as ancillary diagnostic aids, inclusion criteria, or outcome measures.

Sample Population: Sixty-one client-owned dogs with clinical signs of lumbosacral foraminal stenosis.

Methods: A blinded, cross-sectional cohort study. Fifty-one dogs exhibiting apparent lumbosacral pain or pelvic limb lameness with no detected orthopedic cause had blinded review of magnetic resonance imaging (MRI), allowing classification as affected with foraminal stenosis (25 dogs), unaffected (20 dogs), or another diagnosis (6 dogs). The presence of electromyographic changes and tibial neurography variables were compared between groups.

Results: Cord dorsum potential onset latency, F-wave onset latency (both corrected for limb length), and F-ratio were increased in dogs with lumbosacral foraminal stenosis versus those without, although there was overlap of the values between groups. The proportion of dogs with electromyographic changes was not significantly greater in MRI-affected dogs.

Conclusion: Electrophysiological testing is a useful ancillary test, either to provide stricter inclusion criteria and outcome measures or to aid clinical decision-making in equivocal cases.