Anyone, humans and non-humans animals with a nervous system connected to their brain can feel pain, this is because nerve relay sensations to the brain. When the pain signal
reaches the brain it goes to the thalamus, which directs it to a few different areas for interpretations. A few areas in the cortex, figure out where the pain came from and compare it to other
kinds of pain with which is it familiar.
Let’s take a basic example, a horse that gets hit with a whip will remember the object that caused him pain and is likely to be afraid of it as soon as the cortex has figured out what have caused pain. The pain can also be associated with the person using the object that has caused pain.
Signals are also sent from the thalamus to the limbic system, which is the emotional center of the brain. Yes, not only the horse is feeling pain but also he is experiencing a range of emotions such as fear, anger, distress etc. Feelings are associated with every sensation the horse encounter, and each feeling generates a physical response such as increase in heart rate.
To fully understand the harm caused by the bit, one must study the cranial nerves pattern in details and understand that bits can be categorized into two groups:
It is essential to understand that there is absolutely nothing the user can do to stop the horse from feeling the pain inflicted by the bit, this is due to how the bit being created to
work, where it being placed and how the horse’s nervous system is designed.
The diagram below is one of the most comprehensive diagrams I have found. A larger version is available for download at the end of this page.
The first thing to know is that the trigeminal nerves got 3 branches:
DENTAL BITS EFFECT
TRIGEMINAL BITS EFFECT:
Bits are not the only instruments that can cause pain, the rope halter also affects cranial nerves and therefore send pain signal to the brain. VII shows the main branch of the facial nerves. Facial nerves being nerves that are extremely close to the skin and therefore extremely sensitive to pressure applied unto the skin. “Wiggling” a lead rope connected to a rope halter, like recommended by some “Natural” Horsemanship trainers, cause pain as the halter’s knots are placed just on the buccal branches of the facial nerves (8).
Download the diagram below: