Several studies1–6 involving humans and laboratory animals (rats and mice) have revealed that lavender oil can act as a CNS depressant with sedative properties when inhaled, thus improving sleep quality. Some researchers have suggested that in vitro exposure of inotropic G-amino butyric acid A receptors to essential oils can modulate neural transmission, and in vivo exposure may therefore have an effect on mood.7 Results of a study8 performed by our research group suggested that the apparent anxiolytic and antidepressant-like effects of inhalation of lemon oil vapor in mice may be caused by suppression of dopaminergic neuronal activity via enhanced activity of neurons that release 5-hydroxytryptamine. However, similar investigations in dogs are limited because of difficulties in assessing the neurologic and psychologic effects of essential oils.
On the other hand, the mechanisms and degree of absorption and metabolism of chemicals in dogs differ from those in humans; values from assessment of autonomic nerve activity are also different. Therefore, some chemicals that are innocuous in humans might be associated with adverse effects in dogs. For example, ingestion of xylitol, which generally causes no ill effects in humans, causes hypoglycemia and hepatic failure in dogs.9,10 Consequently, we believe that the psychologic effects of essential oils may differ between humans and dogs and that, furthermore, certain essential oils may actually have opposite effects for dogs versus humans.
The purpose of the study reported here was to investigate the effect of topical application of lavender (Lavandula angustifolia) oil on sympathovagal activity in dogs. Our hypothesis was that application of lavender oil would result in reduced sympathovagal activity (an indicator of degree of relaxation), compared with activity when a placebo was applied.
Holter recorder QR2100, Fukuda ME Kogyo, Tokyo, Japan.
Holter jacket, Fukuda ME Kogyo, Tokyo, Japan.
ECG analyzing system HS1000V, Fukuda ME Kogyo, Tokyo, Japan.
Aroma-Vet International, San Diego, Calif.
Essential Oil University, New Albany, Ind.
JMP software, version 5.1.1, SAS Institute Japan Inc, Tokyo, Japan.
Gyllenhaal C, Merritt SL, Peterson SD, et al. Efficacy and safety of herbal stimulants and sedatives in sleep disorders. Sleep Med Rev 2000;4:229–251.
Lewith GT, Godfrey AD, Prescott P. A single-blinded, randomized pilot study evaluating the aroma of Lavandula augustifolia as a treatment for mild insomnia. J Altern Complement Med 2005;11:631–637.
Duan X, Tashiro M, Wu D, et al. Autonomic nervous function and localization of cerebral activity during lavender aromatic immersion. Technol Health Care 2007;15:69–78.
Buchbauer G, Jirovetz L, Jäger W, et al. Aromatherapy: evidence for sedative effects of the essential oil of lavender after inhalation. Z Naturforsch [C] 1991;46:1067–1072.
Lim WC, Seo JM, Lee CI, et al. Stimulative and sedative effects of essential oils upon inhalation in mice. Arch Pharm Res 2005;28:770–774.
Aoshima H, Hamamoto K. Potentiation of GABAA receptors expressed in xenopus oocytes by perfume and phytoncid. Biosci Biotechnol Biochem 1999;63:743–748.
Komiya M, Takeuchi T, Harada E. Lemon oil vapor causes an anti-stress effect via modulating the 5-HT and DA activities in mice. Behav Brain Res 2006;172:240–249.
Dunayer EK, Gwaltney-Brant SM. Acute hepatic failure and coagulopathy associated with xylitol ingestion in eight dogs. J Am Vet Med Assoc 2006;229:1113–1117.
Fujii Y, Wakao Y. Spectral analysis of heart rate variability in dogs with mild mitral regurgitation. Am J Vet Res 2003;64:145–148.
Suzuki A, Tsutsumi H, Kusakabe K, at al. Establishment of a 24-hour electrocardiogram recording system using a Holter recorder for miniature swine. Lab Anim 1998;32:165–172.
Lombardi F, Sandrone G, Pernpruner S, at al. Heart rate variability as an index of sympathovagal interaction after acute myocardial infarction. Am J Cardiol 1987;60:1239–1245.
Matsunaga T, Harada T, Mitsui T, et al. Spectral analysis of circadian rhythms in heart rate variability of dogs. Am J Vet Res 2001;62:37–42.
Graham L, Wells DL, Hepper PG. The influence of olfactory stimulation on the behaviour of dogs housed in a rescue shelter. Appl Anim Behav Sci 2005;91:143–153.
Huikuri HV, Mäkikallio T, Airaksinen KE, et al. Measurement of heart rate variability: a clinical tool or a research toy? J Am Coll Cardiol 1999;34:1878–1883.
Højgaard MV, Holstein-Rathlou NH, Agner E, et al. Dynamics of spectral components of heart rate variability during changes in autonomic balance. Am J Physiol 1998;275:H213–H219.
Zaza A, Lombardi F. Autonomic indexes based on the analysis of heart rate variability: a view from the sinus node. Cardiovasc Res 2001;50:434–442.
Heart rate variability: standards of measurement, physiological interpretation and clinical use. Task Force of the European Society of Cardiology and the North American Society of Pacing and Electrophysiology. Circulation 1996;93:1043–1065.
Egizio VB, Jennings JR, Christie IC, et al. Cardiac vagal activity during psychological stress varies with social functioning in older women. Psychophysiology 2008;45:1046–1054.
Calkins SD, Graziano PA, Keane SP. Cardiac vagal regulation differentiates among children at risk for behavior problems. Biol Psychol 2007;74:144–153.
Saeki Y. The effect of foot-bath with or without the essential oil of lavender on the autonomic nervous system: a randomized trial. Complement Ther Med 2000;8:2–7.
Alaoui-Ismaïli O, Vernet-Maury E, Dittmar A, et al. Odor hedonics: connection with emotional response estimated by autonomic parameters. Chem Senses 1997;22:237–248.
Elisabetsky E, Marschner J, Souza DO. Effects of linalool on glutamatergic system in the rat cerebral cortex. Neurochem Res 1995;20:461–465.
Okuyama S, Sawasaki E, Yokogoshi H. Conductor compounds of phenylpentane in Mycoleptodonoides aitchisonii mycelium enhance the release of dopamine from rat brain striatum slices. Nutr Neurosci 2004;7:107–111.
Tisserand R, Balazs T. Basics. In: Essential oil safety: a guide for health care professionals. London: Churchill Livingstone Inc, 1995;7–22.
Williams DG. The chemistry of essential oils: an introduction for aromatherapists, beauticians, retailers & students. Weymouth, England: Micelle Press, 1996.
Watt M. Plant aromatics: a data and reference manual on essential oils and aromatic plant extracts. Oxford, England: Pergamon Press PLC and Watt M, 1998.
Main components of lavender oil as analyzed by use of gas chromatography–mass spectrometry.
|Compound||Retention time (min)||Area (%)|
|cis-L halool oxide||33.30||0.14|