10/10/2026
The Physiology of Pleasant Touch
I talk a lot about the mechanics behind massage, but there’s another side to the story that I think people don’t understand quite as well: the physiological response to touch the horse actually enjoys.
Touch is sensory information. Receptors in the skin and deeper tissues detect pressure, movement, stretch and other mechanical stimuli and send that information into the nervous system. The brain doesn’t simply register that the horse has been touched. It interprets that information, and the body responds.
When touch is perceived as safe and pleasant, it can influence pain processing, autonomic activity, stress physiology, heart rate and breathing, as well as chemical systems involved in pleasure, relaxation and social bonding.
So although the nervous system plays a central role, this is a much broader physiological response.
There is a biological reason horses have these responses. Horses are highly social animals, and physical contact is part of their natural behavior. Mutual grooming helps maintain social relationships, while close physical contact between a mare and foal begins almost immediately after birth.
These systems help make positive social contact rewarding. They encourage horses to seek and maintain relationships with other horses and can help regulate the body during periods of stress. Massage and other forms of appreciated touch can tap into some of these same systems.
Three responses are particularly important:
1. The horse’s own pain-relieving systems become active
The body has several ways of changing how strongly pain is experienced.
One involves endogenous opioids—opioid chemicals produced by the horse’s own body, including endorphins. These can reduce pain perception and contribute to the comfortable feeling associated with pleasant touch.
But pain relief from touch isn’t simply a matter of “releasing endorphins.”
Touch also sends a large amount of non-painful sensory information into the nervous system. That input can influence the transmission and processing of nociceptive signals—the signals associated with actual or potential tissue damage—at several levels of the nervous system.
In other words, the nervous system can turn the volume of pain information up or down. Pleasant touch can be one of the inputs that helps turn it down.
2. The stress response quiets down
The autonomic nervous system constantly adjusts things the horse doesn’t consciously control—heart rate, breathing, digestion, blood pressure, alertness and many other functions.
When a horse perceives touch as safe and pleasant, autonomic activity can shift away from the heightened arousal associated with vigilance and stress and toward a calmer physiological state.
This can be accompanied by changes in heart rate and breathing, reduced activity of some stress systems, and changes in chemical messengers such as oxytocin.
Oxytocin has several related roles. It is involved in social affiliation and bonding, but it can also influence stress regulation and autonomic activity.
Serotonin is also involved in the regulation of mood, arousal, pain processing and many other physiological functions. It is sometimes described as another chemical “released by massage,” but that is an oversimplification. The serotonin system is complex, and we shouldn’t assume that a relaxed horse is simply experiencing a surge of serotonin. It is more accurate to understand serotonin as one of many signaling systems involved in regulating the horse’s overall state.
This helps explain why a horse enjoying touch may lower his head, soften his expression, breathe more slowly, become quieter or show other signs of relaxation.
We aren’t simply changing the tissues under our hands. The sensory information created by touch can influence the physiological state of the whole animal.
3. The brain makes pleasant touch rewarding
Pleasant touch also interacts with the brain’s reward systems.
Dopamine, endogenous opioids and oxytocin are all involved in different aspects of reward, pleasure, motivation and social affiliation.
This has an important biological purpose. If grooming and close physical contact with trusted companions feel good, horses have a reason to seek those interactions again. That helps maintain social relationships and cohesion within the group.
The brain also learns from repeated experiences. When interaction with another horse—or a person—is consistently safe and pleasant, the horse can begin to associate that individual, situation and type of touch with a positive outcome.
That is one reason some horses don’t simply tolerate massage. They begin to actively participate in it—positioning their bodies, leaning into particular kinds of touch or seeking further contact.
This is the other side of massage.
There are mechanical effects on muscles, fascia and other tissues, but those mechanical effects are only part of what is happening.
At the same time, touch is providing sensory information. The horse receives and interprets that information, and the resulting response can influence pain processing, autonomic activity, stress physiology, chemical signaling, reward and learning.
In other words, what happens under our hands and what happens throughout the horse are happening at the same time.
And that means the horse gets a say.
Touch that one horse finds deeply relaxing may be irritating, uncomfortable or threatening to another. More pressure isn’t necessarily better, and a technique doesn’t automatically produce relaxation simply because we call it massage.
For these responses to occur, what matters is not only what we do with our hands, but how the horse experiences what we are doing.
https://koperequine.com/soothing-touch-improves-immune-system-function/