Lack of Effectiveness of Tramadol for Earlier Limb Weight-Bearing After Femoral Head and Neck Excision in 38 Dogs

The objective of this study was to evaluate, in client-owned dogs, the postoperative analgesic efficacy of the centrally acting analgesic tramadol following femoral head and neck excision (FHNE). Thirty-eight dogs were diagnosed with coxofemoral disease and underwent FHNE. The sample was randomly divided into two groups. Postoperatively, dogs in Group A received robenacoxib (2 mg kg^-1 bodyweight, sid, per os) until they achieved final weight-bearing of the operated limb, whereas dogs in Group B received the same regimen of robenacoxib in combination with tramadol (5 mg kg^-1 bodyweight, tid, per os) for fifteen days. All animals were premedicated, sedated, and anesthetized following the same standardized protocol to ensure consistency between groups. Postoperative evaluations were conducted on days 15 and 30, and subsequently at monthly intervals, until full weight-bearing of the affected limb was achieved. Clinical assessments included observation of pain-related behaviors, lameness scoring, and time to initial weight-bearing (TIWB) and time to final weight-bearing (TFWB). Data normality was assessed using the Shapiro-Wilk test, and differences between groups were evaluated using the independent samples T-test (p = 0.05). Statistical analysis revealed no significant differences between the two groups regarding time to initial (p = 0.087) or final weight-bearing. However, a moderate effect size (d = 0.570) was observed for TIWB, suggesting a clinically interesting trend toward faster early recovery in the multimodal group. These findings indicate that while adding tramadol did not confer a statistically significant additional advantage in this study, the observed clinical trend warrants further investigation in larger, higher-powered cohorts to determine its definitive clinical impact.