Case Report: Oral and topical chronic administration of THC-rich and CBD-rich cannabis oil as palliative care in a rescued horse with open wound, sarcoid and chronic pain.

Overview

• This case report explores the long-term use of combined oral and topical THC-rich and CBD-rich cannabis oils as palliative care to improve the quality of life for a rescued horse suffering from severe chronic conditions including an open wound, sarcoid tumor, and chronic pain.

Background and Rationale

• Cannabinoid-based therapies are known for their potential analgesic (pain-relieving), anti-inflammatory, and wound-healing properties across multiple veterinary species.
• However, there is a lack of clinical data specifically regarding the long-term administration of THC-rich cannabis formulations in horses.
• This gap in knowledge motivated the authors to document and analyze the effects of combined THC-rich and CBD-rich cannabis oil treatment in a horse with severe chronic disease conditions.

Case Description

• Subject: A senior mixed-breed gelding horse rescued with multiple severe health issues:
  • Large, chronic ulcerative lesion on the left hind limb
  • Severe malnutrition
  • Non-weight-bearing lameness, rated AAEP grade 5 of 5 (most severe)
  • Refractory (resistant to treatment) pain
• Diagnostic Findings:
  • Fibroblastic equine sarcoid (a type of tumor)
  • Suspensory tendon rupture (complete)
  • Early stage osteomyelitis (bone infection)
  • Chronic joint disease
• Conventional treatments (both medical and surgical) were limited or ineffective due to disease severity and resource constraints.

Treatment Protocol

• Initiated a palliative care regimen focused on combined cannabinoid therapy:
  • Oral administration of THC-rich and CBD-rich full-spectrum cannabis oils in equal ratio (1:1) at 100 mg/mL for each cannabinoid
  • Gradual dose escalation targeting 0.5 mg per kg body weight of each cannabinoid every 12 hours
  • Topical application of the same cannabis oil formulation to the wound once or twice daily
• Duration of treatment: 10 months
• Multimodal analgesia was used as needed alongside cannabinoid therapy.

Outcomes and Observations

• Positive clinical responses associated with cannabinoid treatment included:
  • Improved appetite and body condition, addressing malnutrition
  • Reduction in pain and increased mobility
  • Significant wound healing progress:
    • Reduced granulation tissue (excess scar tissue) formation
    • Improved epithelialization (regrowth of wound-covering skin)
    • Resolution of self-mutilation behavior (likely related to pain or irritation)
• Safety profile:
  • No significant adverse effects or laboratory abnormalities associated with routine dosing were observed.
  • Transient sedation and ataxia (uncoordinated movement) occurred only at high “rescue” doses near the end of life.

End of Life and Quality of Life Summary

• Despite eventual progression of disease and the need for euthanasia due to refractory pain, the horse’s quality of life was substantially improved for the majority of the treatment period.
• The cannabinoid therapy appeared to be a beneficial adjunct to multimodal palliative care, contributing to pain relief and wound management where conventional therapies were insufficient.

Conclusions and Future Directions

• This case supports the potential role of combined oral and topical THC-rich and CBD-rich full-spectrum cannabis oils as a safe, effective adjunct therapy in chronic, refractory conditions in horses.
• It highlights the therapeutic potential of cannabinoids in veterinary medicine, specifically for equine palliative care.
• The authors emphasize that controlled clinical studies are needed to:
  • Define optimal dosing regimens
  • Clarify specific indications and long-term safety profiles