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Equine Aromatherapy: Applications on Behavioral Issues



With aromatherapy gaining ground in human medicine every day, it also started to attract interest from the veterinarian community especially in Western European countries which in turn led to an increasing number of scientific research in the field. Very much like the human organism, aromatherapy works for animals on a number of different levels: physically, emotionally, conditionally and evolutionary. Horses, in particular, are very sensitive animals and have been shown to benefit from aromatherapy.

On the physical level; especially in cases of musculoskeletal, skin and respiratory system disorders, many veterinarians are already accustomed to working with essential oils (e.g. Eucalyptus (Eucalyptus globulus), Rosemary (Rosmarinus officinalis), Peppermint (Mentha x piperita), Tea tree (Melaleuca alternifolia), etc.), also, several common ready-made equine-veterinary drugs already contain various botanical active ingredients.

Speaking on the emotional/psychological level, as we know, essential oils trigger chemical responses in the olfactory receptors, which in turn forward messages to horses’ limbic system via the olfactory nerve, where the animal’s behavioral responses are generated by emotional stimuli; establishing a sense of calmness, relaxation, stimulation, contentment, or a number of other responses.

A typical veterinarian may already have heard about the merits of walking into the box of an uneasy equine-patient with lavender essential oil. However, in veterinary medicine school, for many veterinarians it is relatively something new to consider the smell on its own as a useful tool for behavioral disorders’ treatment, or that the complementary medicine would significantly improve animal welfare during training, handling, lengthy uncomfortable treatments and or chronic diseases.

In the greater metropolitan area of Istanbul, under the supervision of Doctor of Microbiology, veterinarian Fikret Memişoğlu, a study of equine aromatherapy on horses with behavioral issues was conducted on four equine patients. Upon the completion of the four field studies over an average period of 1.5 months each, the empirical evidence showed that aromatherapy could be used to tackle and solve reported behavioral issues if/when high quality, unadulterated essential oils are used and administered at 5% dilution via inhalation, coupled with preplanned positive reinforcement scenarios that tackle the unwanted behavior patterns.


State-of-Art Review

Since the beginning of the 21st century, the number of aromatherapy studies conducted on horses increased significantly. In these studies, the most common essential oils used to assess emotional responses of horses to various smells have been: Lavender (Lavandula angustifolia), Rose (Rosa damascena), Roman chamomile (Anthemis nobilis), Jasmine (Jasminum grandiflorum), Geranium (Pelargonium graveolens), Lemon (Citrus limon), Bergamot (Citrus bergamia), Frankincense (Boswellia carterii) and Vetiver (Vetiveria zizanioides). In the control groups, researchers commonly used sunflower oil, which does not have a distinct smell on its own. Below I included short summaries of the studies and publications I selected and cross-examined before and over our aromatherapy applications on equine patients with behavioral issues. During the selection of these studies, I paid meticulous attention to the researchers’ area of expertise and background.

In one study, executed with ten horses – five geldings and five mares of mixed breed – nine organic essential oils applied to a ball of cotton wool plus a control (no oil) were presented to horses. The textile preparations were hung on either side of the stable doors. Horses were exposed to five presentations on a single day, and the subjects’ behavior was recorded while investigating the aromas. At the end of the two day period, researchers established that – out of the nine different essential oils plus one control – the horses demonstrated a significant interest in Peppermint (Mentha x piperita), Violet (Viola odorata), Valerian (Valeriana officinalis), and Lavender (Lavandula angustifolia). (Hurley & Goodwin, 2008)

Another study models an experimental treatment of humidified Lavender (Lavandula angustifolia) essential oil as well as Chamomile (Matricaria recutita) essential oil along with control of humidified air on eight dressage horses. Researchers recorded the heart rate variability (HRV) of the subjects 7 minutes before, during, immediately after and 30 minutes after treatment. Based on the HRV data, the study concluded that lavender is an effective calming agent for horses, while chamomile showed variable effects. (Baldwin & Chea, 2018)

A study on 28 Welsh horses was conducted by dividing the subjects into two groups. Half of the horses were treated with Lavender (Lavandula angustifolia) essential oil in a 10% dilution, whereas the other group received a control substance (vegetable oil). Horses were then subjected to a series of stress tests which did not last more than 30 minutes each. During this time the heart rates, behavioral stress indicators were monitored and saliva samples were collected. Results of this study showed that stress indicators such as heart rate, alert postures, and defecations were lower in lavender oil-treated horses. Salivary cortisol levels were also lower for lavender-treated horses. (Poutaraud, et al. 2017)

In one experiment, seven horses received aromatherapy treatments with lavender (Lavandula angustifolia) essential oil and control over a 7-day apart period. First, the heart rates (HR) and respiratory rates (RR) were recorded for each horse at rest in their stalls. Then an air horn was blown twice for 15 seconds serving as a stress stimulus, after which the horses were allowed to calm for 60 seconds. Then the heart rates (HR) and respiratory rates (RR) were recorded. While the RR did not differ between the control group or the lavender treated aromatherapy groups, lavender essential oil proved to significantly decrease heart rates after the acute stress response elicited by the stress stimulus. (Ferguson, Kleinman, & Browning, 2013)

In a crossover study, researchers examined eight horses transported in a horse trailer for 15 minutes. During the ride (stressor), the horses received water aromatherapy as the control and lavender aromatherapy (Lavandula angustifolia). Each horse had three blood draws measured: one before being loaded into the trailer, immediately after the trailer ride (stressed) and an hour after the trailer ride. By determining the serum cortisol levels from blood samples, this study concluded that the blood serum cortisol levels were lower in horses which were subject to lavender aromatherapy during the trailer ride (stressor). (Heitmana et al. 2018)

Another study with two replicated trials investigated the behavioral effects of essential oils on 12 stabled horses divided into three groups. During the first trial, 12 essential oils as drops on wooden blocks were separately presented to the animals. The horses’ behavior, namely the mean duration of olfactory investigation of the blocks were video recorded to construct a mean attractiveness order for the 12 oils. The three most attractive oils detected during the first trial – Rose (Rosa damascena), Roman chamomile (Anthemis nobilis) and Peppermint (Mentha x piperita) – were then used for the second trial. During the second trial, these three oils, in addition to a control specimen (sunflower oil), were presented individually to each horse for five days. On odd days (day 1, 3, and 5) their behavior was recorded for 30 minutes using wall-mounted video cameras. The researchers’ analysis of the data showed a significant effect of the treatment on the duration of the horses’ movement, and the time they spent standing alert. The “Wilcoxon Signed Ranks Tests” of the same study for treatment differences showed that Rose and Roman Chamomile resulted in a significant reduction in movement, suggesting increased relaxation. Differences between Peppermint and the control were not significant. The researchers concluded that “In these short-term trials the horses demonstrated increased attraction to Peppermint, Rose and Roman Chamomile essential oils. Although many published studies have shown the stimulating effects of Peppermint oil on dogs, the results of this study did not render any results to demonstrate similar effects in horses.” (Glover & Goodwin, 2006)


Methodology

Horses as being prey animals have developed a very strong sense of smell connected to their limbic system to ensure survival at large. As several trials, studies and experiments have shown, aromatherapy proved to be an effective tool, which can be, and may be used to alter horses’ state of mind, ease suffering by distracting them from chronic pain, and to make them more responsive and cooperative to handling, training or behavioral modification.

Below, I would like to present the procedure and its steps for a typical treatment on equine patients that I have been following on regularly.

The methodology adopted for the aromatherapy applications for behavioral issues starts – in co-operation with a responsible veterinarian – with a thorough examination of their medical history.

After establishing that the reported behavior is not due to any physiological issue, an assessment of the social behavior is carried out by the team of its trainers, owners and caretakers.

It is also important to investigate whether the equine-patient have endured any traumatic incidents. With the qualitative historical data collected, the first step is the essential oil selection phase.

In equine aromatherapy, for deciding on the proper application for behavioral issues, essential oils are selected in two phases.

In the first phase, the appropriate essential oils for the specific case are chosen; in the second phase a set of pre-determined essential oils are presented to the equine patient for selection.

When treating behavioral issues, it is vital to work with essential oils to which the equine patient visibly responds. If the equine patient turns away from a given essential oil, it means that the oil is not attracting the animal, hence, unlikely to be beneficial.

Once the horse selected the essential oil, they are diluted (to 5%) with jojoba oil (Simmondsia chinensis) because in their pure form they are too concentrated for horses, whose sense of smell is much stronger than of humans. Generally, the essential oil is safe to use if the equine patient licks it.

The week following the selection phase (initiation), the equine patient is offered the essential oils chosen earlier in its own box “after training and feeding” – this is usually the time when the animal feels safe and is at ease after the day’s work. This phase is done daily by the caretaker around 4 pm. He picks up the essential oil that the horse has chosen, and offers it for smelling from his palm until the equine patient loses interest.

A week later, depending on the case, the essential oil is presented to the horse via an in-box diffuser at strategic times (therapy) or the treatment moves on to the ground exercises phase for behavior modification.

Ground exercises generally take place on Tuesdays, which is the equine-patients’ ‘back-to- school’ day after resting on Monday. The ground exercises begin with forming an intimate connection between the horse and me, the therapist using the chosen essential oil. Via nasal administration of the essential oils, the equine-patient usually develops instant trust.

In a particular case, the horse picked up the scent even though it has only seen me once at the initiation phase. When I moved, the equine-patient moved. When I stopped, the equine-patient stopped.

This kind of follow-up is usually used to create positive reinforcement. whereby the horses are lead by the chosen essential oil for behavior modification scenarios – by creating positive experiences at the instances where the behavior issues show up.

Equine Patient Profiles

Equine patient 1: Racehorse

A fresh racehorse had a turning problem; it was constantly circling in his box, which was both risky as he could hurt himself and also a waste of his precious energy that should have preserved for the racing. His history included a series of operations that separated him from his friends in their early years. During the healing period, he rested in his box while his friends socialized in the field.

Chosen ESSENTIAL OIL: Turkish rose (Rosa damascena), “Ranch Synergy”

Results: I met this horse in a countryside ranch. First, we put him in a box from where he could see the fields. We used Rosa damascena for the initiation phase. As a result of the treatment routine, his turning problem was completely gone in two weeks, so we stopped the treatment. Later in the year, he was transferred to the racetracks in the city. There he had no view from his box at all. He started making circles again despite the continued use of Rosa damascena essential oil. At that point, I decided to create a blend that included Atlas cedarwood (Cedrus atlantica), Vetiver (Chrysopogon zizanioides), Lavender (Lavandula angustifolia) and Blue chamomile (Matricaria recutita). We started diffusing the blend in his box early in the morning before feeding, than in the evening after his track training. We also placed a picture of green fields in the box. Again he calmed down. Although the turning problem did not go away completely, as it happened at the ranch, it became tolerable.

Equine patient 2: Show jumping horse 1

This horse had a stopping problem when you rode him on the right-hand side of the exercise rectangle (manége). According to his owner, his previous rider only rode on the left-hand side and never trained him on the right-hand side. Our mission was to make him trainable on the right-hand side and decrease or diminish his stopping and refusal.

Chosen ESSENTIAL OIL: Lavender (Lavandula angustifolia)

Results: After he was initiated with Lavandula angustifolia in his box, I started working to achieve mirroring behavior. Once we got there, I only walked on the right-hand side for days then we proceeded with little trots with me holding a few drops of Lavandula angustifolia oil in my palm. As a next step, we started doing these exercises with a rider in saddle but not demanding work. In about a month and a half, our equine patient became cooperative and his riders started doing light training on the right-hand side without the stops and refusals.

Equine patient 3: Show jumping horse 2

This equine patient was very panicky and showed antagonistic behavior against her stable friends passing by even when she was safe in her box. Sudden sounds freaked her out – no matter how subtle they were. My main downside to the case was that the horse’s past was unknown to the owners as she was transported to Turkey as a gift from a Dutch stable.

Chosen AROMA: Turkish rose (Rosa damascena) hydrosol

Results: Interestingly, this equine patient did not respond well to any of the essential oils presented to her. Just before giving up all hope, I tried Rosa damascena hydrosol, and we were all set! Following the initiation phase, the daily program I created involved grooming her with Rosa damascena hydrosol twice a day. The treatment helped her tense muscles relax, and she started stretching her neck as well. Reportedly, her appetite improved, and the variety of noises she previously responded to decreased. My sessions with her involved spending one on one time in her box, or outside with other horses passing by. I also tried deliberately walking her past by other horses. Her antagonistic behavior was quite hard to break, but one day, instead of giving her the hydrosol, I tried spraying the horse that passed by. It worked. She was confused and could not decide if she wanted to be mad or not. We kept repeating the same exercise and her aggression became less noticeable.