Introduction

Degenerative lumbosacral stenosis (DLS) in dogs results in compression of the cauda equina. The main clinical signs are low back pain and pelvic limb lameness. Treatment may consist either of rest and anti-inflammatory drugs or of decompressive surgery. Evaluation of the result of surgery can be done subjectively, through interviews with the owner, or objectively, by force plate analysis (FPA) of the gait of the dogs.

Aim of study

The aim of this study was to investigate the long term follow up after decompressive surgery in dogs with DLS using FPA and questionnaires to owners.

Materials and Methods

Thirty-one dogs with DLS underwent decompressive surgery consisting of dorsal laminectomy. FPA was performed before, and 3 days, 6 weeks, 6 months and > 1.5 years after surgery. Questionnaires were answered by owners before and at 6 months and > 1.5 years after surgery. Force plate data were analysed using the peak braking force (Fy+), the peak propulsive force (Fy-), and the peak vertical force (Fz+). The ratio between the total propulsive force of the pelvic limbs and that of the thoracic limbs (P/Tfy-) was calculated.

Results

The Fy- of the pelvic limbs and the ratio P/Tfy- were significantly smaller in dogs with DLS than those in the control group. The Fy- and P/Tfy- were significantly decreased at 3 days after surgery, and the values increased from 6 weeks to 6 months after surgery. The questionnaires reported significant improvement at 6 months and at > 1.5 years compared with questionnaires before surgery. The majority of owners were satisfied with the results of surgery.

Discussion

Decreased propulsive forces in dogs with DLS and at 3 days after decompressive surgery may be the result from impairment of neural tissues. The Fy- and P/Tfy- increased over a 6 months follow-up period, but remained smaller than those in control dogs. Owners' questionnaires illustrate that decompressive surgery reduces the pain and restores normal companion animal function as experienced by owners. It is concluded that surgical treatment of dogs with DLS may result in restoration of propulsive force of pelvic limbs over a period of 6 months.