06/22/2026
Everyone whose horse "is just that way" can take a seat for a minute... time to be personally victimized. Your horse may not just be "that way" 🙈
(and they also could be a little spoiled but that's not what we are talking about... looking at you barrel racers... kidding... kinda)
Let's talk about the TMJ (temporomandibular joint). An uncommon injection site? Maybe not as uncommon as you think.
The TMJ is one of the most frequently used joints in the horse's body. Even at rest, horses are using this joint. From chewing hay and grain to carrying a bit under saddle, the TMJ is constantly working, and for some horses, that can mean inflammation, dysfunction, or pain.
The TMJ does not work independently. It is closely connected to the poll, hyoid apparatus, neck, tongue, and surrounding muscles. Because of these connections, discomfort in the TMJ can sometimes appear as a training issue, resistance under saddle, or a performance problem rather than an obvious lameness.
While many horses will never require treatment of the TMJ, others can benefit from therapies such as corticosteroids, regenerative medicine, or synthetic joint support products designed to reduce inflammation and improve joint function.
Signs that may warrant a discussion with your veterinarian include:
• Stiffness, resistance, or pulling against the bit
• Uneven rein contact or resistance on one side
• Difficulty bending or reluctance to flex laterally
• Changes in performance without an obvious lameness
• Excessive yawning before or after exercise or while eating
• Abnormal tongue movement, such as consistently hanging the tongue to one side
• Head tilt during work or while standing at rest
• Clicking or popping while chewing
• Teeth grinding (bruxism)
• Head shaking or sensitivity around the ears, poll, or jaw
• Difficulty chewing, dropping feed, or eating more slowly than normal
• Difficulty accepting the bit despite proper dental care and well-fitting tack
• Muscle asymmetry of the face, poll, or neck
• Favoring one side while chewing or carrying the bit
These signs do not automatically mean your horse has TMJ pain, but they can be worth mentioning to your veterinarian. Horses experiencing discomfort in this area may compensate through the poll, neck, shoulders, or back, creating secondary soreness patterns elsewhere in the body.
Dental health, poll restrictions, cervical discomfort, and even foot balance can influence how the TMJ functions. This is why many horses benefit from a team approach involving your veterinarian, dentist, farrier, chiropractor, and bodywork professionals.
A thorough examination can help determine whether the TMJ is contributing to the issue or if another underlying cause is present. As with many things in performance horses, interrupting the pain can be an important first step while determining why the pain exists in the first place. Finding and addressing the underlying cause, while helping keep the horse comfortable, gives them the best opportunity for long-term success.
Sometimes the horse that won't bend, won't soften, won't accept contact, or suddenly changes their behavior isn't being difficult... they may simply be trying to tell us that something hurts.