Horse Talk

Deciduous teeth that are not shed can be problematic in young horses in training, warns Dr Mac.

Tooth caps are the name equine dentists give to the thin remnants of deciduous (baby) teeth that are shed in young horses as permanent teeth break through their gums. Generally, these are lost naturally during grazing; however, sometimes they remain in place and prevent the eruption of the permanent teeth. This can also cause pain and lead to difficulties during training, with some horses being difficult to lead. Rearing, bucking, evading the bit and head shaking also present as symptoms of this condition. Understanding tooth eruption can help you recognise capping as a possible cause for a young horse being ‘difficult’.

The front teeth used for tearing off mouthfuls of grass are called incisors. There are twelve of them: six in the upper jaw and six in the lower jaw. Canines or ‘tushes’ are the sharp teeth found in the gap between the incisors and the check teeth. There is one on each side in both upper and lower jaws and they erupt at between four and five years of age, mainly in male horses. Wolf teeth are small pre-molar (cheek) teeth that sometimes erupt, mainly in the upper jaw, between six and 18 months and are usually extracted by dentists.

The cheek teeth in horses have flattened, irregular surfaces and are used for chewing and grinding up hard grasses and grains to make them easier to swallow and digest. There are two types: premolars (12 teeth) and molars (12 teeth). These form an ‘arcade’ (surface for grinding) of teeth on both sides in the upper and lower jaws. The premolar teeth have a deciduous stage that is eventually shed as ‘caps’ when the permanent teeth erupt. Adult molars and premolars erupt at the same time.

retained caps

Most of the time, caps are shed naturally when permanent teeth grow up through the gums and loosen them. It’s not advisable to pull out or remove deciduous teeth as this can cause damage or uneven growth, or a change in direction of the underlying permanent teeth. The deciduous tooth cap fits in between the teeth on each side and keeps them apart until the permanent tooth is nearly level with the biting surface, before it falls off.

Capping can occur in incisors and premolars. The affected horse will often show pain and excessive salivation when eating or grazing. In the short term, the capping of the emerging incisor or premolar usually results in pain, inflammation and infection that can make the

Dr. Mac ABOVE: A dentist holds a tooth cap that was removed from a young horse, showing how it inhibited growth of the permanent incisors and caused inflammation and infection in the gums.