The aim of this study was to evaluate the efficacy of oral transmucosal (OTM) cannabidiol (CBD), in addition to a multimodal pharmacological treatment for chronic osteoarthritis-related pain in dogs. Twenty-one dogs were randomly divided into two groups: in group CBD (n = 9), OTM CBD (2 mg kg⁻¹ every 12 h) was included in the therapeutic protocol (anti-inflammatory drug, gabapentin, amitriptyline), while in group C (n = 12), CBD was not administered. Dogs were evaluated by owners based on the Canine Brief Pain Inventory scoring system before treatment initiation (T0), and one (T1), two (T2), four (T3) and twelve (T4) weeks thereafter. Pain Severity Score was significantly lower in CBD than in C group at T1 (p = 0.0002), T2 (p = 0.0043) and T3 (p = 0.016). Pain Interference Score was significantly lower in CBD than in C group at T1 (p = 0.0002), T2 (p = 0.0007) and T4 (p = 0.004). Quality of Life Index was significantly higher in CBD group at T1 (p = 0.003). The addition of OTM CBD showed promising results. Further pharmacokinetics and long-term studies in larger populations are needed to encourage its inclusion into a multimodal pharmacological approach for canine osteoarthritis-related pain.

The aim of this study was to compare the sedative and physiological effects following either oral transmucosal (OTM) or intramuscular administration of dexmedetomidine–methadone combination in healthy dogs. Thirty dogs were randomly assigned to receive a dexmedetomidine–methadone combination either by the OTM (n = 15) or intramuscular (n = 15) route. Sedation was scored 10, 20, and 30 min after drugs administration. Heart rate (HR), non-invasive blood pressure (NIBP), respiratory rate (f_R), and body rectal temperature were recorded before drugs administration and then every 10 min for 30 min. Propofol dose required for orotracheal intubation was recorded. Sedation scores increased over time within both groups with higher values in intramuscular group (p < 0.05). Within each group, HR decreased significantly compared with baseline (p < 0.001) and was significantly lower in intramuscular group compared with the OTM group (p < 0.001). In both groups, NIBP increased significantly compared with baseline (p < 0.05). In the intramuscular group, f_R was lower compared with the OTM group at all the observational time points (p < 0.001). Propofol dose was lower in the intramuscular group (p < 0.05). Compared to intramuscular dexmedetomidine–methadone, OTM combination produced lower but effective sedation in healthy dogs.