Herbal Medicine in Veterinary Patients

ByNarda G. Robinson, DVM, DO, FAAMA
Reviewed/Revised Sept 2022

Herbal (botanical) medicine involves the practice of prescribing plant products, or products derived directly from plants, for the treatment of disease. Herbal medicine has survived since prehistoric times, in part because, until recently, there were no effective alternatives. Some plants do contain biologically active ingredients, and some pharmaceuticals in widespread use today are identical to, or derivatives of, bioactive constituents of historic folk remedies. Indeed, herbal and botanical sources purportedly form the origin of as much as 30% of all modern pharmaceuticals.

Evidential support concerning use of plant products in veterinary patients is scarce and ranges from effective and safe to ineffective and risky. However, the methodologic quality of primary studies on herbal medicines for many species is generally poor. Trials usually lack firm endpoints, and periods of observation are usually short; the clinical relevance of the observed effects is not always clear. In addition, data that directly compare herbal remedies with well-established pharmaceutical products are often not available. However, as the database on herbs continues to grow, veterinarians seeking to prescribe natural, plant-based compounds should always review the latest scientific literature for information on the compound or product of interest.

Making a rational decision about an herbal product requires knowledge of its active ingredients, its safety and adverse effects, and whether the herb has been shown to be as good as or better than pharmaceutical products available for the same purpose. This information is incomplete or unavailable for most herbal products. In addition, there are no standards or quality control testing of the products regularly recommended for animals. Risk versus benefit questions must be considered for products with unclear constituents and unknown or undisclosed (ie, proprietary) ingredients.

When treating pain, for example, veterinarians seeking to incorporate botanical treatments should consider the type of discomfort being treated (eg, inflammation, myalgia, mental/emotional/physical distress), along with patients' comorbidities, intolerances, and current medications. Adding herbs to the mix has the potential to affect plasma concentrations of coadministered pharmaceuticals.

Table

The table Common Botanical Products in Veterinary Medicine includes a diverse group of examples comprise a diverse group of phytotherapeutics commonly considered to treat pain and/or inflammation. Caution is warranted when implementing such approaches because a full compilation of risks and benefits and therapeutic and toxic doses is largely unavailable.

Botanical Products in Veterinary Medicine
Frankincense oleoresin gum from one of four Boswellia species
Frankincense oleoresin gum from one of four Boswellia species

A photograph of frankincense oleoresin gum from a Boswellia spp. The herb boswellia, also called “Indian frankincense,” harkens back to the ancient practice of ayurvedic medicine. Its main constituent, boswellic acid, confers anti-inflammatory and anti-arthritic effects by inhibiting 5-lipoxygenase and cyclooxygenase-1 production as well as NF-kappa B signaling, among other processes. Frankincense trees are almost extinct.

... read more

Courtesy of Dr. Narda Robinson.

Fresh turmeric rhizome (Curcuma longa)
Fresh turmeric rhizome (Curcuma longa)

Photograph of a fresh tumeric rhizome (Curcuma longa), a member of ginger family. Research on curcumin, the most intensively studied constituent of turmeric, suggests anti-inflammatory, immunomodulatory, neuroprotective, and antiproliferative actions; and clinical benefits. Reports of fraudulent and/or lead-contaminated ground turmeric spice preparations have increased in recent years.

... read more

Courtesy of Dr. Narda Robinson.

Ginger (Zingiber officinale) rhizome
Ginger (Zingiber officinale) rhizome

A ginger (Zingiber officinale) rhizome. One of the world’s oldest botanical remedies, ginger remains popular for its apparent digestive, antinausea, anti-inflammatory, and other healthful benefits. Despite its widespread usage, practitioners need to remain cognizant of ginger being included in the notorious “4 Gs” grouping (ginkgo, ginseng, ginger and garlic) - four plants with anticoagulant/antiplatelet effects that could complicate surgical procedures via unanticipated or excess bleeding.

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Courtesy of Dr. Narda Robinson.

Whole, dried reishi (Ganoderma lucidum) mushroom cap
Whole, dried reishi (Ganoderma lucidum) mushroom cap

Whole dried reishi (Ganoderma lucidum) mushroom cap. One example of a range of Asian medical mushrooms sought for their purported immune-enhancing and anticancer effects. Its most prominent, pharmacologically active compounds include triterpenoids and polysaccharides (especially beta-d-glucans).

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Courtesy of Dr. Narda Robinson.

Sliced, dried reishi (Ganoderma lucidum) mushroom
Sliced, dried reishi (Ganoderma lucidum) mushroom

Photograph of dried, sliced, reishi (Ganoderma lucidum) mushroom. This form allows for the preparation of broths and decoctions, ie, typical methods of extracting desired constituents.

... read more

Courtesy of Dr. Narda Robinson.

Medicinal Mushrooms
Medicinal Mushrooms
Asian medicinal mushrooms hold promise for their immunomodulatory and anticancer benefits. That said, every botanical p... read more

Courtesy of Dr. Narda Robinson.

Milk thistle (Silybum marianum) seeds
Milk thistle (Silybum marianum) seeds

Photograph of milk thistle (Silybum marianum) seeds. Silymarin, the most prominent active constituent of milk thistle seeds, demonstrates hepatoprotective, antioxidant, and anticancer benefits. Although many veterinarians recommend milk thistle derivatives for patients with liver disease, few are familiar with the actual plant product.

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Courtesy of Dr. Narda Robinson.

Yunnan Baiyao (Paiyao) capsules
Yunnan Baiyao (Paiyao) capsules

Photograph of Yunnan Baiyao capsules. This proprietary Chinese herbal formulation is sometimes prescribed to veterinary patients as an adjunctive approach to preventing or slowing hemorrhage, especially for conditions such as hemangiosarcoma in dogs, shock and other causes of bleeding. However, the mechanisms of action, its level of effectiveness, and whether it is safe are unknown, because insufficient research exists. Moreover, not all products labeled as Yunnan Baiyao contain the same ingredients, and many aspects remain undisclosed, untested, and unregulated.

... read more

Courtesy of Dr. Narda Robinson.

Yunnan Baiyao
Yunnan Baiyao
In this video, Dr. Robinson discusses the many unknowns of Yunnan Baiyao (the "red hit" pill). This proprietary Chinese... read more

Courtesy of Dr. Narda Robinson.

Cannabis capsules containing cannabidiol (CBD) and other derivatives from hemp (Cannabis sativa)
Cannabis capsules containing cannabidiol (CBD) and other derivatives from hemp (Cannabis sativa)

Photograph of capsules containing cannabidiol (CBD) and other hemp (Cannabis sativa) derivatives. Unregulated and often untested cannabis products sold for veterinary use may contain proprietary mixtures of cannabinoids, terpenes, and flavonoids. Although early studies suggest potential benefits for osteoarthritis and seizures in dogs, uncertainties persist regarding quality control, contents of proprietary remedies, herb-drug interactions, and the impact of long-term use.

... read more

Courtesy of Dr. Narda Robinson.

Preparations of Herbal Medicine in Veterinary Patients

Botanical products come in a variety of preparations intended either for ingestion or external application. They may be fresh, dried, or freeze-dried; extracted and preserved in oil, alcohol, or water; and delivered as liquids, capsules, pills, poultices, or powders. The type of delivery method affects shelf-life, bioavailability, risk of contamination and adulteration, and acceptability to the recipient.

The term "essential oils" refers to highly concentrated forms of plant-derived substances rich in terpenes or terpenoids. The use of these volatile, rapidly evaporating oils obtained from the leaves, stems, flowers, seeds, or roots of a plant by clients and some veterinary practitioners is growing despite minimal scientific evidence of effectiveness or safety.

Although certain essential oils such as lavender, administered via inhalation, have shown apparent value anecdotally for dogs as antianxiety agents, much remains unknown about safe and effective dosing, purity, and the consequences of chronic exposure. Considering the differences in olfactory sensitivity and the impact of scents on neurologic activity across species, diffused essential oils that people may find pleasant could negatively impact a dog or cat. Furthermore, essential oils pose a considerable danger to birds, with potentially lethal consequences.

Essential oils applied to the fur or directly to the skin may injure or kill an animal through oral ingestion or transdermal absorption. Examples of such dangerous oils include pennyroyal oil and tea tree oil, both of which have documented evidence of causing fatalities in small animals. As an indicator of its toxicity, pennyroyal has a long history of usage as an abortifacient.

Traditional Chinese Veterinary Herbal Medicine

The philosophical approach of the practitioner tends to dictate the type(s) of herbs prescribed. Science-based methodologies rely on pharmacologic evidence and translational insights to consider the pros and cons of assorted plant products for veterinary patients. In contrast, metaphorical and metaphysical approaches such as traditional Chinese veterinary herbal medicine tend to incorporate folklore and unvalidated diagnostic strategies such as tongue and pulse "diagnosis." They also rely on metaphorical concepts such as Yin, Yang, Wind, Heat, and Dampness to inform or determine product selection. In addition, Chinese "herbal" mixtures may contain endangered flora or fauna, as well as insects, worms, heavy metals, undisclosed pharmaceuticals, and a host of other ingredients. Furthermore, manufacturers may sell products as "proprietary," without disclosing each included constituent and its amount. This puts patients and practitioners at risk, especially when a veterinarian recommends a Chinese veterinary herbal remedy with undisclosed quantities of herbal strychnine (a potent neurotoxin) and/or aconite (cardiotoxic and neurotoxic).

Traditional Chinese Veterinary Herbal Medicine
Strychnine and aconite
Strychnine and aconite
Dangers can arise when practicing Chinese herbal medicine and/or homeopathy because of reliance on beliefs rather than ... read more

Courtesy of Dr. Narda Robinson.

Dried, sliced aconite (Aconitum carmichaelii) root, Chinese herb
Dried, sliced aconite (Aconitum carmichaelii) root, Chinese herb

Photograph of dried, sliced aconite (Aconitum carmichaelii) root. Like strychnine, aconite has also found its way into modern traditional Chinese veterinary herbal medicine preparations. Reports of deaths from arrhythmia and shock after ingestion of this toxic plant have not dissuaded some Chinese remedy manufacturers from selling veterinary formulae with aconite in undisclosed quantities. Veterinary personnel need to remain vigilant about the risks of Chinese herbs and to routinely inquire about the use of these and all other supplements.

... read more

Courtesy of Dr. Narda Robinson.

Seeds from the strychnine (Strychnos nux vomica) tree; also called “poison nut”
Seeds from the strychnine (Strychnos nux vomica) tree; also called “poison nut”

Photograph of seeds from strychnine (Stychnos nux vomica) tree. These seeds contain about 1.5% strychnine, a highly poisonous and intensely bitter alkaloid. Although strychnine has no recommended medicinal uses, some traditional Chinese herbal veterinary medicine remedies and homeopathic substances contain herbal strychnine in undisclosed amounts, putting veterinary patients at risk.

... read more

Courtesy of Dr. Narda Robinson.

San Bian Wan
San Bian Wan
Some traditional Chinese “herbal” remedies include endangered or threatened animal species or animals raised in inhuman... read more

Courtesy of Dr. Narda Robinson.

Animal-based ingredients such as testes, penis, placenta, and horn found in Chinese “herbal” medicines harbor potential for zoonotic disease transmission. In addition to health concerns, animal-derived products in Chinese herbs contribute significantly to animal mistreatment and the endangerment of certain species. The unknown benefits of most mammal or insect ingredients do not appear to justify administering these agents to veterinary patients.

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