Periodontal disease is one of the most painful conditions that can occur in the horse's mouth and is the number one cause of premature tooth loss in adult horses, potentially able to affect incisors, canine teeth, and cheek teeth.

The periodontium consists of the gingiva (gum), alveolar bone (the socket in which the tooth sits), periodontal ligament (which anchors the tooth in the socket), and the outer layer or cementum of the tooth. Under normal dental conditions food and bacteria do not accumulate between the teeth and horses have defences such as saliva, white blood cells, antibodies, and "good" bacteria. Normally there is a good periodontal seal between a horse’s teeth which prevents feed from becoming trapped and collecting.

Domestic feeding practices, particularly feeds high in sugar or acid, can predispose horses to peripheral caries which can eat away the peripheral cementum and make the periodontal space easier to penetrate by long fibres of food. Feed becomes packed in between or around these now abnormal teeth and undergoes decay and bacterial fermentation. This process causes a breakdown of the periodontium. The gum begins to recede forming a painful periodontal pocket which can then weaken the periodontal attachment of the tooth. This can lead to the displacement of teeth, further opening of periodontal pocket and a vicious circle of dental pathology. The disease may progress towards the root of the tooth and the tooth may become mobile in the socket, leading to tooth loss.

Early recognition of the disease is the first step to successful treatment but it can be very difficult to identify periodontal disease from just the outward signs the horse displays. Signs may include dropping feed, quidding, weight loss, bad breath, and issues whilst being ridden. However, they may also be as subtle as the horse appearing ‘not quite right’. Horses are hard wired not to show signs of dental discomfort and many horses do not exhibit outward signs until there is a severe issue.

Therefore, the easiest way to combat periodontal disease is to catch it early. We recommend all horses have a thorough oral examination with bright light, dental mirror and dental pick / probe, and in some cases even a dental endoscope ("oroscope") every 6 months to a year, by a qualified vet or a BAEDT qualified dental technician. In many cases sedation administered by a vet will be required for this thorough examination.