Oral Transmucosal Cannabidiol Oil Formulation as Part of a Multimodal Analgesic Regimen: Effects on Pain Relief and Quality of Life Improvement in Dogs Affected by Spontaneous Osteoarthritis

SIMPLE SUMMARY: Osteoarthritis is a progressive and degenerative condition that affects dog populations, causing pain. The pain associated with osteoarthritis is considered to be chronic, owing to both active inflammation and to a maladaptive component caused by central sensitization. Chronic pain in dogs is being increasingly recognised as a significant problem, and finding successful treatments against canine osteoarthritis-related pain is challenging. The aim of this study was to assess the efficacy in pain management over a twelve-week period of oral transmucosal cannabidiol, in combination with a multimodal pharmacological protocol, in dogs affected by spontaneous osteoarthritis. Dogs receiving oral transmucosal cannabidiol in addition to an anti-inflammatory drug, gabapentin and amitriptyline showed a meaningful improvement in Canine Brief Pain Inventory scores, in comparison with dogs that did not receive cannabidiol. The present study suggests that the addition of oral transmucosal cannabidiol to a multimodal pharmacological treatment for canine osteoarthritis improves owner reported pain scores and quality of life of dogs, without severe adverse effects. ABSTRACT: 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.