Pet Behaviorist

Below is a portion of the description of the animal's behavior for the query "the horse will pinch its ears and show its teeth as soon as a person approaches it"
A horse that pinches its ears and shows its teeth when approached is likely feeling threatened or fearful. This behavior can be caused by a variety of factors, such as:
Past trauma or abuse
Lack of socialization
Pain or illness
A sudden movement or noise
A new person or object
It is important to first rule out any medical causes for the horse's behavior. Once you have determined that the behavior is not due to a medical condition, you can begin to work on desensitizing the horse to the things that are causing it to feel threatened.