Neurological irritations of the skin and tense muscles, which manifest themselves in hypersensitivity and twitching, can have other causes besides trainingissues or equipment. Internal changes and diseases of the organs can also cause problems on the surface and in the musculoskeletal system, but are often excused with the horse's character or "tickleiness". But what can be behind it?
The nerves that also supply the skin emerge from the intervertebral spaces of the spinal cord (you can see this in the blog post on the spine) and have to pass through the muscles and fascia. In addition, there is a direct connection and two-lane highway between organs - muscles - skin - spinal cord. Consequently, the condition and tension in these areas are essential for neurological signal transmission. If there is compression, overload or changes in one of the areas over a period of time, the nerves in the superficial areas can be disturbed in perception.
A typical example of impaired perception is skin sensitivity. E.g. trembling and twitching at the withers, sensitivity in the stomach or: my horse cannot be touched at the ear!
All of these things can be traced back to muscle tension, fascial adhesions, but also organ problems with associated nerve lesions/nerve irritation. The horses are not, as the common opinion says, "tickley" or just "mares".
Organs as cause
The connections between organ - muscles - skin - and vertebrae are omnipresent. It is already known from the human area that there is often an underlying organ problem as the cause of back pain and tension, which must be remedied if you want to get the problems under control permanently. It's the same with horses.
In mares, muscular problems can often be found in the loin and pelvis area, the mare is aggressive on the hindquarters or on the belly and udder. The mobility is then often stiff: a lack of longitudinal flexibility or movement in the hindquarters. It is interesting that diseases or changes in the area of the uterus or ovaries can very often be detected in these mares. Cysts, tumors, hormone problems or similar can cause this disrupted transmission of stimuli to the spinal cord. However, the spinal cord also reports to associated skin areas and causes disturbed perceptions such as hypersensitivity.
But the intestinal tract can also trigger changes. Stomach ulcers, worm infestation, poor feeding or stress not only trigger a disorder in the organ itself, but also change the transmission of stimuli to the spinal cord, because the organ constantly wants to send the brain an "alarm". The spinal cord in the spine, in turn, reports an alarm to associated skin areas, so-called Head's zones or dermatomes. As a result, for example, a very close muscle area in which the organ is located (e.g. right lumbar muscles for the appendix, belt position for the stomach) but also a distant area can be disturbed via nerves.
So if your horse reacts sensitively, bitchy or even aggressively, you should discuss the health of the gastrointestinal tract but also the urogenital tract with the veterinarian and therapist.
A fantastic view into the 3D Horse Anatomy and the location of the organs in the horse:
Video: Video from the Biosphera.org 3D Horse-Anatomy-Software
Musculature and fascia at the cause
Not only organs, but also fascia and muscles can irritate nerves. Because just as the organ communicates with the spinal cord and the skin via nerves, so does the musculature. Muscle and fascial tension often manifest themselves in sensitive surfaces. But also blockages in the vertebrae, which are caused by tense muscles and fascia, change the transmission of stimuli in the nerve. Typical for this is the skin twitching in the topline on the back, or the sensitivity of the horse on the ear and poll. The nerve can only calm down if the cause (e.g. an unsuitable saddle, poorly seated and influencing rider, excessive demands or bad posture during training, crooked limb loads) is eliminated.
A horse whose skin twitches and trembles, or reacts sensitively and defensively on the top line (e.g. poll and ears), should go through all the causes and ensure relaxation with good posture.