Dental Development in Foals
Did you know that between birth and the first week of life, foals will erupt 16 teeth?
It is a small but important part of both the evolution of the horse and their early development. Why is that the case? It’s connected with a foal’s early ability to begin to graze and to creep feed, which is important for prey species, born well-developed and of significant size. This size and advanced development at birth helps foals to be better able to stay with the herd and to escape from predators.
However, although they are born well developed, there is still very rapid growth over the first few years of life. This growth includes the head, which undergoes rapid changes in size. To assist with this, young horses have several adaptions to both their teeth and their skulls.
- 1
The number of cheek teeth they possess will double between birth and approximately four years of age. This is because the remaining cheek teeth will develop and erupt into the mouth as the skull increases in size and the jaw lengthens to provide the necessary space.
- 2
As the skull enlarges, the position of teeth will change due to forces created by adjacent teeth and tooth eruption.
- 3
Horses’ teeth are divided into two sets: the first set are deciduous or baby teeth, and the second set are permanent or adult teeth. Adult teeth are physically much larger than baby teeth as they are designed to last several decades. However, not all adult teeth are replacing an existing baby tooth, and this is used to classify cheek teeth (which are anatomically the same) into premolars and molars. The premolars are teeth which have a deciduous precursor, whereas the molars are teeth which only erupt in adult form.
The teeth of a foal are made up of three mineralised tissues:
- Enamel,
- Cementum and
- Dentine.
Although all three tissues are similar, they have different properties and can be identified both with the naked eye, and microscopically, from one another. All three tissues begin development within tooth buds inside the embryo. However, some tissues stop development once the tooth erupts (enamel, for example), whilst others remain as living tissue, able to continue development and repair.
The teeth of foals are often very bright white and this comes from the dentine which has yet to stain or discolour. The enamel layer is see-through, or translucent, and so the common misconception that white teeth come from bright enamel is in fact incorrect.
Foals take around six months to possess a full row of deciduous front teeth (incisor teeth), with eruption happening sequentially from the centre at around six days for the central incisors, six weeks for the middle incisors (those directly next to the central incisors) and at around six months for the lateral incisor teeth (those most towards the outside).
Foals are born with very soft cheek teeth; however these teeth very quickly develop sharp points against the youngster’s cheeks and tongue. For this reason, foals will often develop ulcerations within the mouth during the first few months of life, as these sharp points of enamel cut the cheeks and tongue when eating.
Although foals do suffer from many common dental disorders and diseases, this development of sharp points, together with the eruption of the first premolar (more commonly the upper premolars), otherwise known as wolf teeth, at between 6-12 months of age, are still the most important reasons for early dental exams in these young patients.
Young foals do also run into other dental health issues. The following is not an exhaustive list, but rather the more common examples:
- Periodontal disease (commonly referred to as gum disease)
- Cavities or caries,
- Injuries such as tooth and jaw fractures,
- Developmental issues of the jaws and teeth such as brachygnathia (parrot mouth) prognathia (sow or monkey mouth) and campylorrhinus lateralis (wry nose). These developmental issues are congenital, or present at birth.
Whilst owning and breeding young horses should be fun, it’s a good idea to make routine dental care a part of any healthcare program for foals and young horses. An equine dental veterinarian can assist you with this to ensure your new foal avoids any longer-term dental issues. Always seek early advice from your equine vet for foals that might suffer an injury or have congenital issues such as those listed above.
