Concentrations of 15F2t isoprostane in urine of dogs with intervertebral disk disease

OBJECTIVE: To measure 15F(2t) isoprostane concentrations in the urine of dogs undergoing ovariohysterectomy (OHE) and dogs undergoing surgery because of intervertebral disk disease (IVDD) and to assess relationships between urinary concentrations of 15F(2t) isoprostanes and neurologic score in dogs with IVDD. ANIMALS: 11 dogs undergoing OHE and 32 dogs with IVDD undergoing hemilaminectomy. PROCEDURES: Paired urine samples were obtained at induction of anesthesia and approximately 1 hour after OHE (controls) and were collected from dogs with IVDD at induction of anesthesia (28 samples) and approximately 1 hour after hemilaminectomy (31 samples); 26 paired urine samples were obtained from dogs with IVDD. Urinary isoprostane concentrations were measured by use of a commercial ELISA, and results were adjusted on the basis of urinary creatinine concentrations. Differences in the mean isoprostane-to-creatinine ratio were analyzed. Neurologic score was determined in dogs with IVDD by use of the modified Frankel scoring system. RESULTS: Urinary isoprostane-to-creatinine ratios were significantly higher in dogs with IVDD than in control dogs before and after surgery. There was no significant difference between values before and after surgery for either group. There was a significant correlation of neurologic score and urinary isoprostane-to-creatinine ratio because dogs that had higher neurologic scores (ie, less severely affected) generally had higher isoprostane-to-creatinine ratios. CONCLUSIONS AND CLINICAL RELEVANCE: Urinary isoprostane-to-creatinine ratios were higher in dogs with IVDD before and after surgery. Analysis of these data suggests that dogs with IVDD are in a state of oxidative stress and that preemptive treatment with antioxidants warrants further investigation.