A research study at the University of Arizona, conducted by Isabelle Chea and Professor Ann Baldwin, found that lavender has a calming effect on horses and can be used to reduce their stress levels.
Horses face a variety of stressors daily: trailering, bathing, clipping, vet visits, hoof trims, bridling and saddling, to name a few. Using lavender as aromatherapy can be a more natural way to calm them down, rather than using tranquilizers or medicine.
Professor Baldwin teaches a class that uses horses to study heart rate and heart rate variability (the measure of the variations between heartbeats) and both are indicators of stress level. A previous study looked at the heart rate in horses who used aromatherapy in the presence of a stressor, but Chea and Baldwin’s study is the first to look at heart rate variability without any stressors.
“We wanted to test regular horses that aren't stressed out by external forces,” says Baldwin. “Some horses and some breeds, it's just in their nature that they are more stressed. So, we wanted to use horses that were not being scared deliberately to see what effect, if any, the aromatherapy had on them.”
They tested nine dressage horses by monitoring their heart rates and heart rate variability for 7 minutes without a lavender diffuser, for 7 minutes with a lavender diffuser and 7 minutes after the diffuser. They also tested water vapor and chamomile.
They found that lavender was the only scent that produced a calming effect, but only when the lavender was being actively smelled. The horses’ heart rates didn’t change, but the parasympathetic component of their heart rate variability did.
“One of the parameters of heart rate variability is RMSSD, and that represents parasympathetic input, which is the relaxation part of the autonomic nervous system,” says Baldwin. “If RMSSD goes up, that indicates the horse is relaxed. We found that when the horses were sniffing the lavender, RMSSD significantly increased compared to baseline.”
Visibly, the horses also seemed more relaxed and performed behaviors such as neck lowering, licking and chewing.
These findings can be helpful for farriers who work with horses that are skittish or nervous during shoeing.
"Some horses don’t like to be shod. So, when the farrier comes and starts banging around with their hooves, it would be good for that," explains Baldwin. "You don’t need a diffuser, really. Just put a few drops of lavender essential oil on your hand and let your horse sniff."