TMJ Symptoms in Horses

TMJ refers to the temporomandibular joint in horses, located at the rear portion of the lower jaw where it joins the skull. Conditions affecting the TMJ are referred to as temporal mandibular joint dysfunction (TMJD). For conditions affecting the TMJ, an ounce of prevention is worth a pound of cure, and all horses should have annual visits from an equine dentist or veterinarian who works on teeth. Some symptoms of TMJ are subtle and may be mistaken for other causes.

  1. Head Shaking

    • Head shaking may be caused by pain from TMJ, as can shying away from touching of the head, ears, or poll. Any horse with head sensitivity should be checked by a veterinarian for possible TMJ.

    Dental Abnormalities

    • Dental problems resulting from TMJ and lack of regular dental care include uneven tooth wear, misalignment of lower and upper incisors, tooth grinding, and mouth pain. Equine dentistry can correct some of these issues, although aligning the teeth for occlusion in a horse with TMJ may take time. The equine dentist will "float" the horse's teeth using a rasp or drill to even them out. According to the website "Equine Tooth Problems and Dental Care," "If the conditions are allowed to get too severe, corrective dentistry will be required which involves specialized tools and knowledge."

    Colic

    • While TMJ and dental issues are usually not the first reasons that come to mind when a horse colics, it can be a cause of gastrointestinal distress. Colic refers to any gastrointestinal problem in horses. It is serious and often fatal. Call a veterinarian if you suspect a horse is colicing. Those events, which come and go for no obvious reason, may be traced to TMJ due to improperly chewed feed.

    Lack of Appetite

    • In people, TMJ causes headaches. For horses, the pain from uneven molars strains the TMJ, and causes them to stop eating or colic. Any lack of appetite, or what horsemen refer to as "going off their feed," can indicate pain in the TMJ. A horse that stops eating warrants a visit from the veterinarian, as this may also be a precursor to colic.

    Lameness

    • Long-term TMJ affects the way the horse carries itself and uses its body, and can result in uneven gaits and subtle lameness. Maureen Rogers, author of "TMJ and TMD: Exploring the Whole Body Connection," states "Depending on the length of time the condition has existed, it may have worked its way through the entire body, causing the horse to compensate in his work, thus unbalancing him and inhibiting his performance and athletic abilities."

    Chewing

    • Clicking and popping noises heard while a horse masticates its food may be an indicator of problems with the TMJ, as these sounds indicate unevenness in the mouth. Horses who only chew food on one side of the mouth may also have pain in the TMJ.