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Professional Version

Herbal Medicine in Veterinary Patients

By

Narda G. Robinson

, DO, DVM, MS, FAAMA, CuraCore Integrative Medicine & Education Center

Last full review/revision Sep 2022 | Content last modified Sep 2022
Topic Resources

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 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

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

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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