Medicinal herbs can be beneficial to equine health, but competition rules and regulations might prohibit their use in some cases.
Herbs have been used for centuries to enhance the performance of many sporting horses. But whether utilized alone or as an adjunct to conventional medicine, the use of herbal medicine in competition remains an under-researched and controversial topic. A greater understanding and knowledge of herbal medicine within the equine industry will hopefully dispel some concerns, and lead to more appropriate usage to help improve equine health and well-being.
Research in herbs
Evidence is revealing the benefits of including medicinal herbs in the management of equine health. Equine herbal products can boost the immune system, improve antioxidant status, and increase coping abilities and concentration. Herbs have also been beneficial for several equine disorders, including recurrent obstructive pulmonary disease, allergic dermatitis and joint inflammation.
Herbal remedies for performance horses
Herbal supplements that affect the immune system can be classified as adaptogens (which increase resistance to stressors), immunostimulants (which activate the nonspecific, or innate, defense mechanisms) or both.
A number of herbs demonstrate anti-inflammatory and pain-relieving activity.
1. Ginkgo (Ginkgo biloba)
Ginkgo is used with good results in cases of “sport horse anemia”, a common problem for performance horses. This condition reduces oxygen delivery to the muscle cells during effort, thus decreasing the anaerobic threshold, with the ultimate result being loss of performance.
2.Ginseng (Panax ginseng)
Ginseng inhibits inflammation.
3. Ginger (Zingiber officinale)
Ginger can reduce post-exercise cardiovascular recovery time. Many ulcer-relief herbal supplements for horses contain ginger as a major ingredient.
4. Yucca (Yucca schidigera)
Yucca produces anti- inflammatory, antioxidant and anti-spasmodic effects to reduce pain associated with arthritis.
5. Devil’s claw (Harpagophytum procumbens)
Devil’s claw is primarily sold for its pain-reducing properties. It’s also an anti-inflammatory, making it a good choice for horses with joint problems.
6. White willow, meadowsweet and capsaicin
These also have anti-inflammatory and/or analgesic properties.
Adaptogenic studies on exercise capacity in many species have produced conflicting results. So far, practical use in performance horses supports the conclusion that adaptogenic herbs should not be considered performance-enhancing substances, but rather substances that simply support optimal health and function.
Concerns with herbs in competition
Herbal products contain ingredients that are able to affect body systems, and can therefore be prohibited substances in competitions. At the 2008 Beijing Olympics, several riders were disqualified from competition for testing positive for capsaicin (Capsicum frutescens). Capsaicin is banned by the Federation Equestre Internationale (FEI) as it stimulates P substance and has pain-relieving properties. The theory is that after the initial burning sensation, which is associated with heightened sensitivity, a period of reduced sensitivity follows. If capsaicin is rubbed on a horse’s shins just before competing, a rider can time the period of heightened sensitivity associated with the burning to encourage the horse to pick up his legs over the jumps to avoid hurting himself, thereby potentially improving performance. However, capsaicin does not appear on the FEI Medication Class A list of banned substances with other herbs such as valerian, so confusion does exist. Part of the inconsistency may stem from the fact that a test to detect it has only recently been developed.
Rules of equestrian sport affecting herbal usage
FEI (the world governing body for equestrian sports) distinguishes between medication (i.e. veterinary treatment provided to safeguard the animal’s health and welfare) and doping (i.e. the deliberate intent to affect the performance of a horse or to mask an underlying health problem). There are presently three classes of offence: Doping, Medication Class A and Medication Class B. Medication Class A (therapeutic agents that could influence performance (e.g. relieving pain, sedating, stimulating or producing/modifying physiological or behavioral effects) is the category for most herbs (Higgins 2009).
United States Equestrian Federation rules (USEF 2010) are subject to the Therapeutic Substance Provisions, which state: “Trainers, owners, exhibitors are cautioned against the use of medicinal preparations, tonics, pastes, powders and products of any kind, including those used topically, the ingredients and quantitative analysis of which are not specifically known, as they might contain a forbidden substance. This is especially true of those containing plant ingredients. The plant origin of any ingredient does not preclude its containing a pharmacologically potent and readily detectable forbidden substance.”
A further USEF caution states: “Persons administering a so-called herbal or natural product to a horse or pony to affect its performance, having been comforted by claims that the plant origin of its ingredients cause it to be permitted by the rules as well as undetectable by drug tests, might have been misled. Trainers should be most skeptical about any claims by manufacturers or others that their preparation is ‘legal’ or permissible for use at competitions. It is the longstanding policy of USEF that it does not approve, endorse or sanction herbal, natural or medicinal products of any kind.”
Forbidden herbal substances listed in the USEF’s Drugs and Medications Guidelines handbook include belladonna, camphor, capsaicin, chamomile, comfrey, devil’s claw, hops, kava kava, lavender, lemon balm, leopard’s bane, night shade, passion flower, rauwolfia, red poppy, skullcap, valerian and vervain.
Substance detection and screening
The objective of screening is to detect any trace of drug exposure using the most powerful analytical methods. Problems are now arising because the high level of sensitivity in current screening methods allows for the detection of totally irrelevant plasma or urine concentrations of legitimate drugs for long periods after their administration. Therefore, new approaches for legitimate compounds based on pharmacokinetic/pharmacodynamic (PK/PD) principles are being developed.
The detection time (DT) is the approximate period during which a drug (or its metabolite) remains in a horse’s system and can be detected by laboratory analysis. The withdrawal time (WT) for a drug must be decided upon by the treating veterinarian and is likely to be based on the DT plus a safety margin, chosen with professional judgment and discretion to allow for individual differences between horses such as size, metabolism, degree of fitness, etc.
The FEI (2010) states that veterinarians have to advise owners or trainers on appropriate WTs to guarantee that their horses may safely compete after drug administration. DTs typically range between three and ten days. There is no mention of WTs for herbs or herbal extracts.
Inconsistencies in banned substances
There are many discrepancies between the lists of various equestrian organizations. The USEF banned substance list contains herbs by their common names and is more extensive than either those of FEI or the Jockey Club UK.
In contrast, FEI does not list the herb by name; rather it identifies prohibited substances according to their active constituents and the physiological systems upon which they act. Lobeline, an alkaloid of the lobelia plant found in Indian tobacco (Lobelia inflata), cardinal flower (Lobelia cardinalis) and star of Bethlehem (Hippobroma longiflora), is listed as a respiratory stimulant. Valerenic acid, a sesquiterpenoid constituent of the valerian plant, is listed as a tranquilizer. FEI states that it reserves the right to alter the list at any time without prior notice, while USEF makes clear that its current list of banned substances is only partial, perhaps in a concerted effort to stay ahead of potential abusers.
The process by which an herb officially becomes an illegal substance is vague; as a result, all competitors are kept guessing. Consistent regulations regarding herbs may be far off, since the governing bodies for equestrian sports have not come to an agreement on even which drugs should be permitted in competition. In the meantime, exercise caution when using adaptogenic herbs for your performance horse, and check the regulations regularly for updates.
Adapted from “Literature Review: Risks and Pitfalls of Herbs in Sporting Horses” by Kim Chase, JIVT 1(2) October, 2011, civtedu.org. A version of this article previously appeared in IVC Journal.