Can a horse break their tongue bone?

temporohyoid osteoarthropathy THO which weakens the bone.
It is important to be aware that clinical signs can vary greatly depending on the structures that are affected by the fracture which can include nerves and major blood vessels. In many cases of THO or stylohyoid bone fracture the horse will have difficulty swallowing or picking up food.
This is a painful condition and any horse that has problems eating should be assessed by a vet as a matter of urgency. In the early stages of temporohyoid osteoarthropathy the horse may show vague signs such as headshaking bit avoidance face rubbing or dysphagia. In later stages they may show signs of nerve damage the stylohyoid bone is close to certain nerves such as eye problems or a head tilt.
How do we diagnose and manage damage to the hyoid apparatus?
The horse has a pair of structures in the pharynx called the guttural pouches through which blood vessels and nerves run. Each of the guttural pouches left and right are divided into two compartments inside and outside by the stylohyoid bone. It is possible to access the inside of the guttural pouches using endoscopy in the standing horse. And the stylohyoid bone can be visualised through the thin membrane of the guttural pouch. For this reason endoscopy is usually the first form of diagnostic imaging used in cases of dysphagia or suspected stylohyoid disease. In addition to endoscopy radiography CT or MRI can be extremely useful as they can provide information about all of the soft tissue structures that are likely to be affected as well as the bony structures that cannot be imaged using endoscopy.
Some of the reported cases of stylohyoid bone fracture responded well to conservative management rest and pain relief and temporary dietary changes. But treatment will depend on the structures affected. There are some surgical options for cases of THO. But these are not without complications and options would depend on the individual case.
How to reduce risk of damage to stylohyoid and tongue.
Historically it was not uncommon for vets or dentists to examine the horses mouth by pulling the tongue out of the way or using it to gain access to the mouth. Since the development of good equipment and adequate sedation this is generally deemed unnecessary. Although your vet or dentist will move the tongue around the mouth during an oral examination and treatment they will take great care to avoid