Evaluation of CTX-I, CTX-II, TIMP-I, MMP-9 and PIICP in the population of working German Shepherd dogs in Slovakia

The aim of this study was to determine the reference values of cartilage damage biomarkers in the blood and urine in 76 clinically healthy German Shepherd dogs. We grouped the dogs into 4 groups by age. All the groups were consistently made up of 19 dogs. The mean age and average body weight were established for all the dog groups. The blood was collected from the vena cephalica antebrachii or the vena saphena medialis and the urine sample was taken by us-guided cystocenthesis. The biomarkers were determined using quantitative sandwich ELISA kits. The mean values of the biomarkers ± SD were, for the urine biomarkers, CTX-I 3.29 ± 1.16 ng/ml, CTX-II 1 993.95 ± 777.04 ng/ml, and TIMP-I 392.80 ± 160.56 ng/ml, and for the blood biomarkers, MMP-9 89.85 ± 50.21 ng/ml and PIICP 19.19 ± 7.33 ng/ml. Based on the obtained values of the mean 95%, we expect a standard for CTX-I 5.05 ng/ml, CTX-II 3 204.26 ng/ml, TIMP-I 606.64 ng/ml, MMP-9 187.93 ng/ml, and PIICP 31.71 ng/ml.