What tooth is only found in male horses?

It is a male fighting tooth. It's main function for the horse is to do damage to his opponent in a fight. There are normally four of them. Two are located in the upper jaw and two in the lower jaw. They are found in the interdental space of the mouth. This is the part of the mouth between the incisors and molars also called the bars of the mouth. The canines are usually about an inch (2.5cm) or so behind the corner incisors. The bottom two on the lower jaw tend to get quite long and sharp. They are deeply rooted teeth and very strong.