Essential Oil Use in Canine Veterinary Medicine
viii Table of Contents Page Abstract .............................................................................................................................. iv List of Tables ..................................................................................................................... vi Introduction ..........................................................................................................................1 Literature Review.................................................................................................................6 Manuscript 1. Essential Oil Use in Canine Veterinary Medicine: A Survey of the Members of the American Holistic Veterinary Medical Association ........17
Manuscript 2. Essential Oil Use in Canine Veterinary Medicine: Interviews with Members of the American Holistic Veterinary Medical Association ........38
Manuscript 3. Essential Oil Use in Canine Veterinary Medicine: Visions of the Future .55
Manuscript 4. Essential Oil Use in Canine Veterinary Medicine: Methods of Administration ...........................................................................................66
For millennia, essential oils have been used for their beneficial properties. Since the time of the early Egyptians, essential oils have been used to influence behavior, as medicine, for food, for spiritual purposes, and to enhance the immediate environment. (Tisserand 1977:13) Prior to the distillation process currently credited to the early Egyptians, it is likely that aromatic plants were burned or steamed to release their fragrant qualities by people around the world. (Tisserand 1977:17-25) Attention to essential oils has faded, only to emerge again over the centuries. Throughout the past half century or so, essential oils have experienced a resurgence in popularity. (Arnauld-Taylor 1992:3-10) (Price and Price 2007:xi-xiii) While the use of essential oils never ceased, the rise in Western medicine and pharmaceuticals left their use to the folk practitioners and holistic healers who tended to quietly tend to their own families and, perhaps, an isolated community. As one who has practiced forms of natural medicine for decades, I have met dozens of others who learned from grandparents or community members, particularly in the Ozark and Appalachian Mountains and in indigenous communities throughout the world. When it became time to embark on a doctoral dissertation, my attention returned to essential oils. By then dozens of books for both lay practitioners and medical professionals had become available. Laboratory research on essential oils was plentiful. Human uses for essential oils were well represented in academic journals and popular media. Essential oil uses with animals were mentioned, as well, primarily in popular media.
2 What was not well-represented in published material, I discovered, was veterinary use of essential oils. After diligently searching through literature for nearly a year, with little to show for it, I came across a chapter on aromatherapy by Susan G. Wynn and Michael D. Kirk-Smith in Complementary and Alternative Veterinary Medicine: Principles and Practice, (1998) by Allen M. Schoen and Susan G. Wynn that confirmed “The use of aromatherapy in veterinary medicine is largely unexplored.” (p. 561) After speaking with several veterinarians of my own acquaintance on the subject, I found genuine interest, but little knowledge of essential oil use among those I knew to be attentive to natural medicine. I contacted Dr. Wynn in March 2009, and was assured that the use of essential oils in veterinary medicine was an area that remained under- investigated. “That is a field wide open,” she said. Essential oils were used in individual veterinary practices, but there was no general understanding of how and for what reasons. The first step in developing an understanding of essential oil use in veterinary medicine, I decided, would be a general survey of a population most likely to be interested in veterinary essential oil use to determine the scope, method, purpose, and philosophy of essential oil use in veterinary medicine. Because of the large range of species attended by veterinarians, it seemed practical to limit this research to one species. Canine patients were chosen as the research subject most practical for three reasons. One is that dogs are common animal companions and would be present in most veterinary practices. Secondly, aromatherapy with dogs had been mentioned in some of the popular media and among folk practitioners of my acquaintance. And, as one who practices
3 holistic medicine that includes essential oil therapies with my own dogs, I would be able to better evaluate that series of uses than any other. A qualitative, ethnographic approach to this research was chosen for the comprehensive nature of that methodology. The depth of exploration inherent in qualitative, ethnographic research would not only provide the greatest understanding of circumstances, but also lay the most stable foundation possible for further research. The group chosen for survey was the membership of the American Holistic Veterinary Medical Association (AHVMA), whose membership list was available on the Internet. The results from a national survey of that set of veterinarians provide the base and initial findings for this research, and are presented in Manuscript 1. To gain a deeper understanding of essential oil use in canine veterinary medicine, 15 respondents from the nation-wide survey who indicated significant essential oil use in practice, and had agreed to a contact for additional information, were interviewed at depth as to the specifics of essential oil use within their personal experience. The details on their decision processes, methods of administration, and specific essential oils, along with successes and failures of use, have been provided in Manuscript 2. Information provided by the interviewees has been maintained in language as close as possible to the discussions as recorded and transcribed. For clarity in communication, statements have been paraphrased when appropriate. In Manuscript 3, the 15 veterinarians who were interviewed at depth provided a diverse and thoughtful view of the future of essential oil use in veterinary medicine. An additional seven veterinarians who are known in the field of holistic veterinary medicine,
4 most of them published authors, added their views to the likely and possible futures of essential oil use in veterinary medicine. After completing the main work on this dissertation, one aspect in the body of information compiled seemed ripe for further examination. Specifics on the methods of administration of essential oils to canine patients, it seemed, could be explored in more depth than in the original approach to the subject. Documenting the details of essential oil administration would allow for greater and safer use in therapeutic settings. In the original survey of the members of the AHVMA, a common reason given by those who do not include essential oil therapy in their practices was the lack of familiarity, knowledge, experience, or education on how to use them. To further develop an understanding of the details of essential oil applications with canine patients, additional interviews were conducted with veterinarians who had emerged through the original research as some of the best informed and most experienced on the subject of essential oil use in veterinary medicine. Each of the veterinarians interviewed indicated a keen understanding of essential oil therapeutics through the study of aromatherapy, essential oil science, collaboration and consultation with colleagues, and their own practical experience. Manuscript 4 documents specific information on the decision process and details methods of therapeutic administration of essential oils in canine veterinary medicine. Guidelines provided serve as a general knowledge base and beginning point for those interested in including essential oils more fully in veterinary practice.
5 This dissertation represents nearly three years of research on essential oils, in general, and specifically on the subject of veterinary essential oil use with canine patients. The resulting information documented establishes an understanding of veterinary essential oil use with canine patients within the United States, as well as provides a foundation for additional research.
6 Literature Search
Throughout time human beings have appreciated the aromatic qualities of plants. Well into the ancient depths of human history plants have been collected and appreciated for their aromas. Plants were heated or crushed to release reluctant or subtle fragrances, and used in many ways. Specific plants became recognized for their healing aspects, for erotic persuasion, agricultural benefits, and for spiritual purposes. Eventually plant oils became prized, and collected for use whenever desired. No one knows the specifics of the early collection methods of essential oils. The distillation process has been credited to the early Egyptians. From there, the ancient Indians, Greeks, Romans, and Chinese are thought to have borrowed from and added to the distillation technology and numbers of plants used to produce essential oils for multiple uses. (Price 1993) Essential oils were used among early European alchemists and medical professionals. (Price 1993) Eventually essential oils, usually defined as the pure, volatile distillate or extract of a plant (Dodt 1996), found their way to the laboratories of chemists working in the French perfume industry. Renee Maurice Gattefosse is credited with the research and development of essential oils for modern therapeutic use in the home and in hospital settings. He termed his work as Aromatherapie. Gattefosse began his research into the medicinal qualities of essential oils after the arm of his laboratory coat caught fire. He plunged his arm into the nearest liquid: a vat of lavender essential oil. Gattefosse‟s burns healed much more quickly than through any medical treatment. His
7 interest in therapeutic aspects of essential oils was piqued. He dedicated his career to researching medical applications for essential oils. (Wikipedia) (Tisserand 1977) Essential oil therapeutics were further explored and documented by the French physician Jean Valnet. He recorded many uses of essential oils during his years as a physician during World War II. (Valnet 1982) Today essential oils are used in aromatherapy, a therapeutic body of knowledge and application of essential oils. Following the tradition of Gattefosse, only pure plant materials are used. Carrier oils used to apply essential oils to the skin are also pure vegetable oils. (Keville and Green 1995) No synthetics are allowed in products used for aromatherapy. Certain essential oils are extracted in methods that leave traces of natural wax or alcohol. Otherwise, essential oils used in aromatherapy are entirely composed of plant material. Modern medical and other clinical practitioners around the world also use only pure plant essential oils in therapeutic applications. (Schnaubelt 1999) Essential oil use is widely accepted in Europe and the United Kingdom. Examples of their use for multiple purposes are easily found. Essential oils are taken seriously. University courses have been developed for healthcare professionals. (Lis- Balchin 2006) Aromatherapy is probably the fastest growing of the health disciplines in the United Kingdom and possibly in several other countries. (Tisserand and Balacs 2005) Applications and investigations regarding essential oils are much less common in the United States. Essential oil use and applications tend to be disregarded and often subject to ridicule. Even so, essential oil use is not uncommon. Folk practitioners, as well as those maintaining family traditions, have used essential oils for medicine and as
8 insect repellent for millennia. (Muryn 1995; Price and Price 2007; Rose 1992; Tisserand 1977) Such practitioners have developed multiple uses for essential oils that may be explored through research for more widely distributed benefit. New literature in popular media and in academic and scientific sources has begun to appear more frequently. Veterinary use of essential oils is a field largely unexplored in the United States. This is confirmed in a chapter on aromatherapy by Susan G. Wynn and Michael D. Kirk- Smith appearing in Allen M. Schoen and Susan G. Wynn‟s edited text, Complementary and Alternative Veterinary Medicine: Principles and Practice: “The use of aromatherapy in veterinary medicine is largely unexplored.” (1998:561). Two articles on toxicity of essential oils have been published. One discusses the clinical aspects of toxic overdose of tea tree essential oil as marketed for animal dermatological conditions. (Knight, Hansen, and Buck 1994) The other describes the clinical presentation and postmortem examination of a dog who had been doused by her owner with a large quantity of undiluted pennyroyal essential oil. (Sudekum, et al) Most of the material available regarding essential oil use with dogs or other animals is not written by veterinarians. It is, however, read by veterinarians. In 2006 the Journal of the American Veterinary Medical Association published an article from a study in the United Kingdom in which 32 dogs who had exhibited unruly behavior during automobile travel were observed both before and after exposure to an aromatic administration of lavender essential oil. The study concluded that lavender essential oil in the ambient air within the automobile in which the dog traveled resulted in significantly more relaxed behavior. (Wells 2006)
9 Nelly Grosjean is a French doctor of naturopathy and aromatherapy practicing in Provence, France. Her book, Veterinary Aromatherapy, was published in French in 1993 and translated into English in 1994. She provides recipes for therapeutic administration of essential oils with animals. Kristen Leigh Bell completed her master certification in aromatherapy and in 2002 published, Holistic Aromatherapy for Animals. In her book she describes various essential oils and their uses with animals. Aromatherapist and author Jeanne Rose mentions essential oil use with dogs in The Aromatherapy Book: Applications and Inhalations, although the book is almost entirely concerned with human uses. Applications for dogs are somewhat anecdotal, but serve as good examples for beginning exploration into clinical administration. She discusses essential oil blends for dogs. Essential oils are also commonly used in combinations to achieve maximum effect. (Lawless 1995; Worwood 1991) How this seemingly synergistic effect occurs, no one knows. It would be highly beneficial to discover those means for contemporary application. So far, no published academic research that explores the combination of essential oils has been located for this research. Nevertheless, today essential oils are sought for both pleasure and therapeutic value. The range of uses extends from the enjoyment of natural fragrance, to the elimination of bacteria and viruses, to address disease and discomfort, to mental and spiritual aspects that promote relaxation, wellness, and healing. (Dodt 1996; Keller 1991; Keville and Green 1995; Price and Price 2007;
10 Rose 1995; Schnaubelt 1999; Tisserand 1977; Tisserand and Balacs 1995; Worwood 1991) Aromatherapists and medical practitioners are cautioned to question and test any substance labeled as an essential oil. They are advised to deal only with reputable companies in purchasing essential oils. Not all oils labeled as essential oils are of the quality that may be utilized for therapeutic purposes. Some essential oils are “cut,” or extended, with a separate vegetable oil in order to extend the oil and reduce the price or increase profit. Extended oils are often marketed as pure essential oils; however, the practice is considered deceptive. Reputable essential oil producers do not cut the essential oils they produce, unless the product is specifically labeled differently. (Dodt 1995; Keller 1991 and 1992; Tisserand 1977; Worwood 1991) Adulterated oils have been developed for modern fragrances. Certain aspects of essential oils are chemically removed from a pure essential oil in order to standardize the oil for predictability or synthetic reproduction in the perfume industry. (Price 1993) Additionally, to manufacture standardized fragrance and food flavoring, some essential oils have been synthetically reproduced. Typically, only the desired qualities have been chemically recreated. Adulterated and synthetic oils are not used in aromatherapy or any other traditional applications. (Keller 1992; Price and Price 2007; Schnaubelt 1999; Worwood 1991) As essential oil use becomes more popular, medical professionals and chemists around the world have become more curious as to the mode of effectiveness in essential oils. Aside from those involved in adulteration and synthesis of oils, there are those
11 seeking to identify the reasons that essential oils are therapeutically relevant. While many medical practitioners are comfortable with the use of something not entirely understood, chemists have analyzed essential oils in great detail. (Price and Price, 2007) (Schnaubelt 1995) Over 3,000 different molecules have been identified in essential oils. This allows for adulteration and synthesis. It also plays a role in understanding therapeutic application. (Price and Price 2007) One of the most exciting discoveries in essential oil use is the research under way at the University of Manchester where essential oils have been tested to combat deadly, antibiotic resistant bacteria, such as MRSA (Methicillin resistant Staphylococcus aureus) and E-coli. Researchers have found two essential oils that instantly kill both forms of bacteria and have called for their inclusion in soaps, cleaners, and hospital diffusers. The researchers, however, are currently reluctant to reveal the effective essential oils due to “commercial sensitivities.” (BBC NEWS, 21 December, 2004) It would be tremendously beneficial to discover similar possibilities for research through interviews with practitioners in the United States. Many aromatherapists and folk practitioners use essential oils as antibiotics and antimicrobials. It is likely that interviews with them would yield information that could lead to the discoveries similar to those made at the University of Manchester. On average, an essential oil contains one hundred components. (Worwood 1991) Although much is still not understood about the reasons for essential oil effectiveness in
12 therapeutic application, by categorizing the compounds scientists have begun to generate hypotheses as to the ways and means of effects on the body, mind, and spirit. Essential oils are mixtures of aromatic molecules built from the basic elements of carbon, hydrogen, and oxygen. Depending on the types of molecules they contain, essential oils are classified into different chemical or functional groups based on their components. These groups characterize the nature of the whole molecule and its properties. The main groups are terpenes, alcohols, phenols, ethers, aldehydes, ketones, acids, coumarins, and esters. (Keville and Green 1995) Lactones are also included in chemical classification of essential oils. (Price and Price 2007) Terpenes are hydrocarbons consisting of only hydrogen and carbon atoms. Terpenes are further divided into categories including monoterpenes, which have antiseptic, bactericidal, analgesic, expectorant, and stimulating properties. Sesquiterpenes include anti-inflammatory, analgesic, and calming influences. Diterpenes contain additional qualities as expectorants, and may be antifungal and antiviral. (Price and Price 2007) Examples of essential oils in this group are lemon, orange, black pepper, and nutmeg. (Keville and Green 1995) Alcohols consist of a hydroxyl group of one oxygen atom and one hydrogen atom joined to a carbon chain. Alcohols are anti-infectious, strongly bactericidal, antiviral, stimulate the immune system, and appear to have a homeostatic influence on the hormone system. (Price and Price 2007) Examples of essential oils in this classification include sandalwood, clary sage, patchouli, and rose. (Keville and Green 1995)
13 Phenols contain the same qualities as alcohols, plus are antiseptic and activate the body‟s own healing process. They can be damaging to the liver if used in excessive amounts. Phenols also have germicidal and antispasmodic applications. (Price and Price 2007) Examples of essential oils in this category include clove, oregano, and specific types of thyme. (Keville and Green 1995) Methyl ethers are precursors of phenols that include a six-carbon benzene ring attached to a short three-carbon chain. They act upon the components in an essential oil to affect aromatic, flavor, and therapeutic qualities. (Price and Price 2007) Examples of essential oils classified by these characteristics include cedar, basil, and tarragon. (Keville and Green 1995) Aldehydes are formed when the carbonyl radical with a hydrogen atom attaches to one of the carbon atoms in the basic structure. Beneficial properties associated with aldehydes are calming, antiviral, anti-inflammatory, hypotensors, vasodilators, air antiseptics, and antipyretics. Negative properties can include skin irritation and skin sensitivity. (Price and Price 2007; Tisserand and Balacs 2005; Schnaubelt 1995) Examples of essential oils in this group include lemon verbena, lemongrass, and citronella. (Keville and Green 1995) Ketones are formed when a carbonyl group attaches itself, without a hydrogen atom, to a carbon chain structure. Generally, ketones may be sedative, anticoagulant, analgesic, anti-inflammatory, and a digestive aid. (Price and Price 2007) Examples of essential oils in this category include jasmine, peppermint, fennel, sage, and pennyroyal. (Keville and Green 1995)
14 Organic acids and esters are formed by joining an organic acid with an alcohol. They are believed to be antifungal, anti-inflammatory, antispasmodic, and to calm the nervous system. (Price and Price 2007) Esters, according to Keville and Green (1995; 130), are the most balancing of chemical families of essential oils. Examples of essential oils in this family include lavender, ylang-ylang, and bergamot. (Keville and Green 1995) The only oxide known to be relevant in aromatherapy is eucalyptol, which may be regarded as a bicyclic ether. Eucalyptol stimulates mucus glands, is an expectorant, and has antiviral properties. (Price and Price 2007) Lactones occur in expressed oils and some absolutes, such as jasmine, because the molecular weight is too great to allow distillation. An absolute is a concentrated oil prepared through alcohol extraction rather than distillation, and is still a volatile oil, (Rose 1992) which is why they are often included in essential oil application. Lactones are thought to be expectorant and to reduce skin temperature. They may be a neurotoxin and can be phototoxic when ingested in large amounts. Fortunately, most essential oils contain only a small amount of lactones. (Price and Price 2007) Coumarins are present in essential oils only in very low concentrations. Numbering in the thousands, chemists are confident of their effect. Coumarins are anticoagulant hypotensors. They have a sedative and, at the same time, an uplifting effect. (Price and Price 2007) Examples include bergamot, angelica, and citruses. (Keville and Green 1995)
BBC NEWS, 21 December 2004. “Aromatherapy oils „kill superbug‟.”
Bell, Kristen Leigh., 2002. Holistic Aromatherapy for Animals: A Comprehensive Guide to the Use of Essential Oils and Hydrosols with Animals. Findhorn Press, Scotland, UK.
Dodt, Colleen. 1996. The Essential Oils Book: Creating Personal Blends for Mind & Body, Storey Communications, Penal, VT.
Gattefosse, Renee-Maurice. (1937) 1993. Gattefosse’s Aromatherapy, Translated and edited by Robert B. Tisserand, C. W. Daniel Company, Ltd., Essex, England.
Grosjean, Nelly. 1994. Veterinary Aromatherapy: Natural Remedies for Cats, Dogs, Horses, Birds, and for the Rearing of Farm Animals. C.W. Daniel Company, Ltd.
Keville, Kathi., and Mindy Green. 1995. Aromatherapy: A Complete Guide to the Healing Art, The Crossing Press, Freedom, CA.
Knight, Michael J., DVM., Steven R. Hansen, DVM, MS., and William B. Buck, DVM, MS. 1994. “Toxicity of Melaleuca Oil and Related Essential Oils Applied Topically on Dogs and Cats.” Veterinary and Human Toxicology, 36:139-142.
Lis-Balchin, Maria. 2006. Aromatherapy Science: A Guide for Healthcare Professionals, Pharmaceutical Press, London, UK.
Price, Shirley. 1993. Shirley Price’s Aromatherapy Workbook, Thorsons/Harper Collins Publications.
Price, Shirley and Len Price. 2007. Aromatherapy for Health Professionals, Third Edition, Churchill Livingstone Elsevier.
Rose, Jeanne. 1992. The Aromatherapy Book: Applications & Inhalations, North Atlantic Books, Berkeley, CA.
Schnaubelt, Kurt, Ph.D. 1998. Advanced Aromatherapy: The Science of Essential Oil Therapy, Healing Arts Press, Rochester, VT.
Schnaubelt, Kurt. 1999. Medical Aromatherapy: Healing with Essential Oils, Frog, Ltd. c/o North Atlantic Books, Berkeley, CA.
Schoen, Allen M. and Susan G. Wynn, Editors. 1998. Complementary and Alternative Veterinary Medicine: Principles and Practice, Mosby, Inc., St. Louis, MO.
Sudekum, Margaret, DVM., Robert H. Poppenga, DVM, PhD., Narayan Raju, DVM, PhD., W. Emmett Braselton, Jr., PhD. 1992. “Pennyroyal Oil Toxicosis in a Dog.” Journal of the American Veterinary Medical Association, 200:817-818.
Tisserand, Robert B. 1977. The Art of Aromatherapy; the Healing and Beautifying Properties of the Essential Oils of Flowers and Herbs, C.W. Daniel Company, Ltd., Essex, England.
Tisserand, Robert., and Tony Balacs. 2005. Essential Oil Safety: A Guide for Health Care Professionals, Churchill Livingstone.
Valnet, Jean, M.D. 1990. The Practice of Aromatherapy: a Classic Compendium of Plant Medicines & Their Healing Properties, Healing Arts Press, Rochester, VT.
Wells, Deborah L. PhD. 2006. “Aromatherapy for Travel-Induced Excitement in Dogs.” Journal of the American Veterinary Medical Association, 229:694-697.
Worwood, Valerie Ann. 1991. The Complete Book of Essential Oils & Aromatherapy, New World Library, San Rafael, CA.
17 Manuscript 1.
Manuscript title: Essential Oil Use in Canine Veterinary Medicine: a Survey of the Members of the American Holistic Veterinary Medical Association Author: Elizabeth Rowan Keith Date: March 5, 2010 Submitted to the Journal of the American Holistic Veterinary Medical Association
Essential Oil Use in Canine Veterinary Medicine: a Survey of the Members of the American Holistic Veterinary Medical Association
Elizabeth Rowan Keith
In the summer of 2009 members of the American Holistic Veterinary Medical Association (AHVMA) received a survey printed on yellow paper with an accompanying letter requesting assistance and information for a doctoral dissertation research project on essential oil use in canine veterinary medicine. The response to the survey went beyond expectation, and was full of encouragement from AHVMA members for not only the survey research, but also for additional work on essential oils and inquiry into multiple additional aspects of holistic veterinary medicine. This enthusiastic response has been met with sincere appreciation. And out of respect for the one repeated request of the survey respondents that the survey results be published in the Journal of the American Holistic Veterinary Medical Association, this article now appears. In addition to