SummaryStudy design: Experimental study.Objective: The aim of this study was to evaluate the effect of nandrolone decanoate (ND) on the time taken for bone consolidation in dogs undergoing tibial tuberosity advancement surgery (TTA).Materials and methods: Seventeen dogs that underwent TTA surgery were randomly divided into two groups: group C (TTA; 9 stifles), and group TTA+ND (TTA and systemic administration of ND; 8 stifles). Three observers (two radiologists and an orthopaedic surgeon), assessed bone consolidation by visual inspection of serial radiographs at intervals of 21 days following surgery.Results: There were no differences in median weight and age between groups, nor between the medians of the variables right and left stifle. Only weight and age values were normally distributed. The other variables, right and left stifle and time to consolidation, showed non-normal distribution. Meniscal injury was present in all animals in group C and all animals in group TTA+ND. There was a significant difference between time to consolidation in groups C and TTA+ND (p <0.05). One animal in the group TTA+ND showed increased libido. Kappa agreement among observers on radiographs was 0.87.Conclusion: Administration of ND reduces time to bone consolidation in dogs undergoing TTA.Supplementary Material for this article is available online at https://doi.org/10.3415/VCOT-16-09-0130