Dental pain or disease could be to blame if your horse is displaying behavior problems, especially new ones. Researchers have shown that owners and riders can easily miss behavior problems caused by dental pain and, if left untreated, dental pain and disease can lead to more severe health and behavior problems.

Leena Karma, DVM, EVDC, owner of Porvoon Hevosklinikka, an equine dental clinic in southern Finland, notes that signs of periapical (relating to the apex of the root of the tooth) infection, such as dropping feed (quidding), weight loss, and nasal discharge, coupled with behavior problems or changes in head carriage, could indicate dental pain and infection. “We need to keep in mind that horses are prey animals, and they are very talented in hiding pain,” Karma says. “Dental diseases develop gradually, and horses may find ways to adapt to the situation.”

Behavioral Signs of Dental Problems in Horses

Karma stresses that early diagnosis is the key to preventing severe dental disease. “Unwanted behavior should not be overlooked; owners should look for the cause of new behaviors in their horse,” she says.

If horses’ dental pain becomes chronic, the resulting behavior changes can negatively impact performance, says Catherina Foreman-Hesterberg, DVM, equine primary care instructor at the University of Illinois Veterinary Teaching Hospital, in Urbana.

“The health and appropriate equilibrium of the teeth come into effect with the horse’s performance, depending on their level,” says Foreman-Hesterberg. “Dentistry fits into performance when they have an acute change. The head carriage isn’t as comfortable or normal as it used to be. It is extremely important to identify issues before they get to the point where they’re in chronic pain, or we have an infected tooth that needs to be surgically removed.”

Underscoring just how subtle signs of dental-related issues can be, Foreman-Hesterberg suggests watching for repeated behaviors in the stall.

“Even small behavioral changes in the stall versus under tack can be significant, especially if it’s repeatable,” she says. “If it’s a one-time episode, no big deal. But if it’s the same thing over and over again, like they take a bite of grain, step back, turn their head, and chew sideways every time they eat, that’s something that needs to be addressed.”

Besides quidding and head-tilting while chewing, behavioral indicators of dental pain and disease include packing feed in the mouth and struggling to maintain weight despite being on a high-quality diet and in a good training program. “I have noticed some horses take the bit when you’re putting their bridle on, and then start to do abnormal behaviors like a yawn or wrench their jaw back and forth,” Foreman-Hesterberg says.

“Diagnosing dental problems also requires close observation under saddle,” says Alison LaCarrubba, DVM, Dipl. ABVP, associate professor at the University of Missouri’s College of Veterinary Medicine, in Columbia. With significant problems such as fractured teeth, abscesses, and other advanced dental disease, owners start seeing ridden behaviors such as dropping behind the bit.

“Being able to distinguish between dental pain and behavioral problems confuses horse owners,” says LaCarrubba. “Certain owners have a good sense of what’s normal for their horse versus subtle abnormalities associated with the head and neck region.”

Bad Behavior vs. Painful Teeth

Foreman-Hesterberg cautions against automatically assuming performance issues are rooted in behavior problems rather than pain. As both a veterinarian and horse owner, she notes it could be easy to immediately assume a horse is simply misbehaving, especially if it’s a young horse.

“If the rider notices a continuous pattern of behavioral issues like snatching or jerking at the bit, you should explore dental pain as the possible cause,” she says. “If the horse doesn’t take the bit well or wants to be behind or in front of the bit, and this is a constant pattern, no matter what the rider or trainer is doing, there’s an underlying issue.”

It can be easier to detect dental issues in senior horses than in young horses that might be more stoic, and whose pain is more likely to be mistaken for a behavior problem. Loose or fractured teeth and ulcers in the mouth lead to difficulty chewing feed and hay. The most common signs of dental disease in senior horses are hay balling up in the cheeks, and significant weight loss. Tooth issues in old horses can lead to dangerous complications in the digestive tract, such as choke and impaction colic.

Takeaway Advice for Horse Owners

Researchers have shown that untoward behavioral signs associated with eating, riding, and handling can often be reduced with correct dental care. Because it can be difficult for owners to recognize the connection between dental problems and unwanted behaviors, Karma says routine dental checks are critical to a horse’s general health and performance.

“As an equine veterinary dentist, I would recommend that owners find a veterinarian with an interest in dentistry to examine the teeth at least once a year,” she says.

LaCarrubba stresses the importance of those exams being thorough– all teeth counted and inspected (with a mirror and/or oral endoscope) before any work is done. Owners should also be prepared to take the horse to an equine veterinary dental specialist if dental pathologies (disease or damage) are found.