Investigation of timing of surgery and other factors possibly influencing outcome in dogs with acute thoracolumbar disc extrusion: a retrospective study of 1501 cases

Background Intervertebral disc extrusions in the thoracolumbar region are a common spinal neurologic disorder in dogs and usually considered a neurological emergency. Several factors, like timing of surgery, have previously been analysed in order to determine the effect on outcome and time of recovery. Most studies have investigated one defined population of dogs and the influence of a single factor on the overall outcome. In this retrospective study, a large cohort of dogs and the influence of one or combinations of several factors on outcome and time of recovery were analysed. Results The bivariate analysis demonstrated a significant association between the following variables and the time of recovery: the time span between the onset of clinical signs and surgery (Cramers Phi φ^' = 0.14; P = 0.003), the grade of severity ( φ^' = 0.23; P < 0.001) and the implementation of physical rehabilitation ( φ^' = 0.2; P < 0.001). However, the analysis of a multivariable regression model demonstrated that a significant correlation only exists between the time span between the onset of clinical signs and surgery and the overall outcome (P = 0.007), as well as between the grade of severity and the time of recovery (P < 0.001). The percentage of dogs with lacking deep pain perception (DPP) that had to be euthanised due to their neurological condition, decreased from 20.0 to 2.9