It is not uncommon in practice to be asked to examine a horse for a lump on the head of a horse. The inability of the horse to inform us how and when the lump started can make diagnosing the cause of these a challenge at times. As with most medical problems, it is only with a correct diagnosis that the correct treatment can be instigated. Sometimes other signs of disease elsewhere in the body, eg. lungs, may assist in reaching a diagnosis, and so a complete clinical examination is necessary.
As with much of the horse's body, the most important age for its mouth is the teething period, where it changes from primary (deciduous or baby) dentition to secondary (permanent or adult) teeth. Between the age of 2½ and 4½ years of age, the horse will shed 24 baby teeth — both premolars (cheek) and incisor (front) teeth. These teeth are replaced by adult teeth.