Intra-Articular Autologous Conditioned Serum Alone or Combined with Oral Cannabidiol in Dogs Undergoing Tibial Plateau Leveling Osteotomy: An Exploratory Randomized Controlled Trial.

Ardaum P.; Kashemsant N.; Wibulchan W.; Pooliam J.; Vijarnsorn M. · Veterinary sciences · 2026

**Background & Methods** This exploratory randomized controlled trial evaluated intra-articular autologous conditioned serum (ACS), alone or combined with oral cannabidiol (CBD), following tibial plateau leveling osteotomy in 27 dogs (n=9 per group: placebo, ACS, ACS+CBD). Outcomes measured inflammatory markers (C-reactive protein), functional assessments (lameness, pain, weight-bearing), pain inventory scores, radiographic findings, and safety parameters. **Key Findings** • C-reactive protein (CRP) peaked on postoperative Day 1 across all groups; the ACS+CBD combination showed significantly lower CRP compared to placebo on Days 3 (adjusted p=0.007) and 5 (adjusted p=0.001), though sensitivity analyses yielded model-dependent results with uncertain clinical relevance. • Treatment group (p=0.001) and visit timing (p<0.001) showed significant effects on CRP, but the treatment-group×visit interaction did not reach statistical significance (p=0.053), limiting interpretability of group differences over time. • No consistent treatment-group differences were identified across clinical outcome measures (orthopedic assessment scores, Canine Brief Pain Inventory) or structural/radiographic outcomes. **Dosage & Administration** Not reported. The abstract does not specify CBD dosage, frequency, or duration of oral administration, nor details on ACS preparation protocols or intra-articular injection volumes. **Safety & Adverse Effects** One dog in the ACS-treated group developed a surgical site infection. Alkaline phosphatase activity was significantly elevated in the ACS+CBD group on postoperative Day 28 compared to other groups. The clinical significance of elevated alkaline phosphatase requires further investigation. **Evidence Quality** This exploratory trial represents low-to-moderate evidence with significant limitations: small sample size (n=9/group) limits statistical power; primary outcomes did not consistently differentiate treatments; CRP findings are described as "hypothesis-generating" with "uncertain clinical relevance"; sensitivity analyses demonstrated model-dependent results, suggesting findings may not be robust; absence of between-group differences in clinically relevant outcomes (pain, lameness, weight-bearing) undermines practical utility; and the mechanism linking CRP reduction to functional improvement remains unclear. The authors appropriately characterize this as an exploratory study requiring larger confirmatory trials. Classification: Level II evidence (RCT with limitations).

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