BRUXISM IN HORSES

• Bruxism, also known as teeth grinding, is the medical term given to describe the rhythmic movement (side to side) of the molars causing a grinding crunching or scraping sound.
• Bruxism is not a specific sign for a particular problem it is often a sign of a physical or a psychological issue.
• Bruxism is frequently an indicator of a painful condition in both foals and adult horses.
• In foals, bruxism is often associated with the occurrence of gastric ulcers, which is considered to be related to early or sudden weaning and the feeding of concentrates.
• In adult horses, repetitive tooth grinding is often observed in horses experiencing local pain, and often once the painful condition has been dealt with the horse stops the behaviour.
• As in foals, bruxism has been recorded in horses with gastric ulcers.
• Bruxism is also observed in horses suffering from certain neurological conditions. It is also associated with many other conditions from dental pain, through to lead poisoning.
• Teeth grinding is also seen in horses who are experiencing pain associated with being ridden - in this case the cause may be due to the training methods, the equipment or the riders behaviour
• Discomfort can be expressed by the horse in various ways, and teeth grinding has been suggested as one sign of ill-fitting equipment such as a pinching saddle, tight-fitting nosebands and bit action (although mouthing the bit should be considered distinct from bruxism).
• There are many anecdotal reports of teeth grinding occurring in association with different bit types.
• Horse experiencing pain or discomfort will frequently grind their teeth when a bit is placed in their mouth; in addition this sort of grinding may also be caused through tension or conflict.
• Teeth grinding, where the horse only performs the behaviour in the stable, when being groomed or saddled, may become compulsive.
• Sudden onset of teeth grinding must be investigated in relation to clinical problems, since it is likely to be due to pain.
• Longer term more fixed bruxism, with continuous grinding involving the side to side movement of the jaw may in time lead to wear of the molars, and as such, oral problems that could cause pain and/or feeding issues.
• It may also be a sign of stress or discomfort associated with being ridden and this needs to be investigated to find out what aspect of being ridden is causing discomfort for the horse
• A clinical examination should always be undertaken to identify if there is a physical problem with the horse. 
• This includes oral examination, endoscopy to determine if there are indications of gastric ulceration and other clinical investigations and interventions to determine the source of the pain.

For More information

http://www.vetstream.co.uk/fellowes-farm/html/pdf/Factsheets/Horse/24_290775.pdf