Equine Research on the Short-Term Effects of Cannabidiol for the Treatment of Chronic Pain and/or Anxiety
Equine Research on the Short-Term Effects of Cannabidiol for the Treatment of Chronic Pain and/or Anxiety
Dr. James Baumgartner, a Ph.D.,Biochemistry and Pharmacology from Washington State University and Lawrence Dukes, MAS, Johns Hopkins University
Abstract— Cannabidiol (CBD) is one of the major non-psychoactive cannabinoids produced by Cannabis sativa L. Hemp is classified as a Cannabis varietal because it has less than 0.3% tetrahydrocannabinol (THC) – the psychoactive component found in Cannabis.
Recent studies have shown that CBD has good tolerability and a wide range of reported health benefits. The purpose of this study was to measure the effects of CBD increase movement and promote calmness in horses. CBD was studied in horses after the administration of two oral doses (50 mg each) each day over a two-week timeframe.
Fortyone horses were studied across the United States and participants were obtained through relationships with horse shelters, rescues, farms with retired show and race horses, and general pleasure horse farms.
In all of the cases, the horses were evaluated and determined, at the outset, to have impaired movement & presentation and/or demonstrated common vices of anxiety like cribbing, pacing or reluctance to load to trailers or gates.
INTRODUCTION
Routine nonsteroidal anti-inflammatory drug (NSAID) treatments, phenylbutazone and Banamine® (flunixin meglumine), may not provide adequate relief of chronic pain due to diagnosis like musculoskeletal injuries or osteoarthritis and might have potential side effects that preclude its use, particularly in geriatric patients with certain comorbidities, such as gastrointestinal ulceration, especially of the stomach and large colon or (more rare) kidney damage or bleeding disorders. Reactions to allergies have also been reported.
Clinical studies in horses have shown that oral meloxicam has fewer negative effects on the permeability of the gastric mucosa than phenylbutazone (D’Arcy-Moskwa et al, 2012) and that oral meloxicam was not associated with the same reduction in blood albumin concentration that was seen following 13 days’ administration of phenylbutazone (Noble et al, 2012).
There are also differences in the anti-inflammatory effects of the available NSAIDs, as demonstrated in recent studies of experimentally-induced acute synovitis in the horse. Oral administration of meloxicam significantly reduced inflammatory mediators such as substance P and
Thunes, Clair. “Hemp for Horses: Safety and Uses – The Horse.” The Horse, 26 Feb. 2019, thehorse.com/167382/hemp-forhorses-safety-and-uses/. Oke, Stacey. “Understanding Chronic Pain – The Horse.” The Horse, 11 Feb. 2018, thehorse.com/120271/understandingchronic-pain/. Equine Research on the Short-Term Effects of Cannabidiol for the Treatment of Chronic Pain and/or Anxiety Dr. James Baumgartner, a Ph.D.,Biochemistry and Pharmacology from Washington State University and Lawrence Dukes, MAS, Johns Hopkins University
Matrix metalloproteinase activity within synovial fluid (de Grauw et al, 2009), while no reduction in these mediators was observed in horses treated with phenylbutazone (de Grauw et al, 2014). These studies also showed that meloxicam reduced inflammation induced cartilage catabolism, which phenylbutazone did not. This suggests that meloxicam is a good choice for the treatment of acute inflammatory orthopedic conditions.
Few studies comparing the analgesic efficacy of the available NSAID products have been published in horses. In a recent blinded study of 77 horses with chronic lameness, meloxicam was shown to have equivalent analgesic efficacy to phenylbutazone (Olsen et al, 2016). It also appears that analgesic efficacy may depend on the inciting cause of orthopedic pain, with meloxicam demonstrating superior efficacy to phenylbutazone in a model of acute synovitis, but not in a model of mechanical lameness (Banse et al, 2017).
The endocannabinoid receptor system is known to play a role in pain modulation and attenuation of inflammation (5–7). Cannabinoid receptors (CB1 and CB2) are widely distributed throughout the central and peripheral nervous system (8–10) and are also present in the synovium (11).
However, the psychotropic effects of certain cannabinoids prevent extensive research into their use as single agents for pain relief (5, 12). The cannabinoids are a group of as many as 110 different compounds that possess complex polypharmacology that may or may not act through the CB receptors. One cannabinoid, cannabidiol (CBD), may actually be an allosteric noncompetitive antagonist of CB receptors (13).
In lower vertebrates, CBD is reported to have immunomodulatory (14), anti-hyperalgesic (15, 16), antinociceptive (17, 18), and antiinflammatory actions (5, 19), making it a potential therapeutic option in equines with chronic pain or osteoarthritis (OA). Currently there are few companies distributing nutraceutical derivatives of industrial hemp, rich in cannabinoids for animals, yet little scientific research regarding safe and effective oral dosing has been done.
"Horses are able to ‘cover’ their pain due to the presence of a built-in pain suppression response that mammals have, which is called ‘stress-induced analgesia,’ or SIA," explains Ann Wagner, DVM, MSc, Dipl. ACVP, ACVA, a professor in anesthesia at Colorado State University’s (CSU) College of Veterinary Medicine & Biomedical Sciences. "Essentially, SIA explains how a racehorse that suffers a serious leg injury during a race can keep galloping despite the jockey’s efforts to pull it up."
Nora Matthews, DVM, Dipl. ACVA, a professor of anesthesia at Texas A&M University’s College of Veterinary Medicine, adds, "The pain scales we have are designed for specific types of pain such as orthopedic pain or colic, but the equine industry needs a pain scale that can provide a good assessment of all types of pain."
Wagner encourages owners to take the time to assess their horses’ behavior daily and be aware of the more subtle signs of pain. These can include lameness; restlessness; head-lowering; teethgrinding; flaring of nostrils; sweating; rigid posture; head turning toward the flank; kicking at the abdomen; reluctance to be handled; flight behaviors; and aggression.
Other signs of chronic pain are weight loss; shifts in social behavior such as allodynia (e.g., a horse that normally enjoys being petted now shows aversion being groomed or petted); changes in eating, drinking, and sleeping patterns; and decreased response to stimuli.
Note: All information on this page is for informational purposes only and is the property of the study organizer. CannaHorse makes no representation through the sharing of this material.
Source: https://www.panacealife.com/wp-content/uploads/2020/02/Final-Equine-Study.pdf
