Sedative and anesthetic-sparing effects of perioperative full-spectrum cannabis oil in female dogs undergoing unilateral mastectomy and ovariohysterectomy

The anesthetic management of female dogs with mammary neoplasia, usually classified as ASA II and undergoing invasive procedures such as mastectomy and ovariohysterectomy, requires effective sedation and anesthetic stability due to the increased anesthetic risk associated with advanced age and underlying disease. In this context, this study aimed to evaluate the sedative effects and reduction in anesthetic requirements of a full-spectrum cannabis oil (FSCO) containing cannabidiol (CBD) and tetrahydrocannabinol (THC) in female dogs undergoing mastectomy and ovariohysterectomy. Twenty dogs were randomly assigned to two groups: group A (n = 10), treated with FSCO (0.02 mL/kg PO; 0.2 mg/kg CBD and 0.12 mg/kg THC) twice daily for seven days, plus 0.2 mL/kg (2 mg/kg CBD; 1.2 mg/kg THC) one hour before premedication; and group B (n = 10), treated with placebo. Groups A and B had similar ages (9.6; 10.2 years) and weights (7.4; 6.8 kg). Anesthesia was induced with propofol and maintained with sevoflurane. Outcomes included sedation scores, anesthetic requirements, rescue analgesia, responses to instrumentation, and adverse effects. The treated group required less propofol (2.33 vs. 5.98 mg/kg; p = 0.001) and lower sevoflurane concentrations from T0 to T4 (p < 0.05). Sedation scores were higher at 40 and 60 min (median of 4 vs. 0, and 6.5 vs. 0.5; p = 0.015 and p = 0.002, respectively). Fewer treated dogs required rescue analgesia (3/10 vs. 6/10; p = 0.178). No differences were observed in catheterization, intubation, or adverse effects. Preoperative CBD/THC oil produced sedative effects and reduced anesthetic requirements without clinical complications. These findings support the potential of cannabinoids as safe adjuvants in multimodal anesthesia in veterinary medicine.