Equine dental disease can cause pain, disrupt digestive health, compromise welfare, provoke behavior problems, and might even lead to poor performance, said Agnese Santi, Med.Vet., Cert. AVP Equine Dentistry, an independent practitioner in Tuscany, Italy.

For good equine dental health and overall welfare, horses need regular dental checkups and day-to-day monitoring by those who understand equine dental health. “Until a couple of decades ago, we thought floating teeth was good enough, but now science is increasingly (underscoring) the impact of good dental care on horses,” Santi explained, speaking at the 2025 Horse XP Experience for Wellness Conference, held March 15-16 in San Marcello Piteglio, Italy.

How Horses’ Teeth Grow

Horses have hypsodont teeth, meaning they continuously grow out of the jaw, little by little, throughout their lives. Santi said hypsodont teeth are an evolutionary solution to overcome the constant wear on wild horses’ teeth as they chew for much of every day. However, most domestic horses don’t have a diet like wild horses and, contrary to popular belief, hay doesn’t wear teeth the same way grass does.

Horses’ teeth contain four types of living tissue, arranged from the outer surface to the center:

• Cementum;
• Enamel;
• Dentin; and
• Pulp.

You can see all the tissues except the pulp on the chewing surface, arranged in wavy patterns. The pulp, a highly sensitive living tissue, often lies just beneath the surface and progresses outward as the tooth grows. For that reason, equine dental providers can’t just completely reshape extra-long teeth all at once.

Santi explained that when too much time passes between dental visits—say, more than a year and a half—correcting overgrown teeth becomes risky. Removing too much tooth at once can expose the sensitive pulp, causing pain and potentially killing the tooth. That’s why following the dental schedule set by your veterinarian or equine dentist matters.

Common Oral Pathologies in Horses and Why They Happen

Multiple factors can contribute to poor equine dental health, such as:

• Sharp points and edges, which cut the sides of the mouth and the tongue and usually occur because domestic horses don’t evenly wear down their teeth, which again are constantly erupting;
• Hooks, essentially the same as above but they protrude in a way that blocks the opposing teeth from sliding properly or limits the jaw’s full forward-to-back (rostrocaudal) movement, which can interfere with neck flexion;
• Anisognathism, in which the top and bottom jaw are different widths—common in donkeys—creating uneven wear that forms points and hooks;
• Diastema, which describes an abnormal space between teeth where food gets stuck and packed, causing pain, swelling, and infection, though it frequently goes undiagnosed; and
• Soft-tissue lesions, including cuts from deformed teeth, sharp objects (such as a wire hidden in hay), or bits; ulcers from embedded foxtail plants; and tumors.

Horses can also get cavities, she said. Teeth sometimes crack, creating small fissures in the surface dentin that allow bacteria to enter and break down the tooth from within. Left untreated, this decay can lead to infection, pain, and even tooth loss.

The frequency and quality of dental care, the type of diet, and the phase of the horse’s life—youngster, adult, or senior—play significant roles in dental health, said Santi. So do genetics because breeding choices rarely take oral health into consideration. In addition, individual horses can have slightly different chewing biomechanics, altering how their top and bottom teeth slide across each other.

Poorly fitted bridles and bits can also cause mouth pain by placing uncomfortable pressure on the teeth, bones, and soft tissues, and by restricting natural jaw movement. “There’s only a small layer of tissues that separates the external ridges of the upper teeth from the bridle,” she explained. “With (inappropriate) pressure, you can really risk doing a lot of damage.”

Signs of Dental Pain in Horses

Researchers have demonstrated that horses exhibit they’re in pain through facial signs, postures, and behaviors—leading to the development of tools such as the horse grimace scale (HGS) and the ridden horse pain ethogram (RHpE), Santi said.

Recently, scientists have linked certain types of behaviors to mouth pain, she said. For example, horses with toothaches or other oral pain might show any of the following:

• Quidding (dropping feed or hay from the mouth) or showing other signs of difficulty eating;
• Showing reluctance to accept the bit;
• Shaking the head and avoiding bit pressure;
• Avoiding handlers—turning away in the field or at the stall door; and
• Showing aggression toward humans and/or other horses.

If a toothache is to blame, removing the affected tooth generally leads to rapid improvement in these behaviors, Santi said. Even so, many owners miss these signs or confuse them with other problems. “Owners need more training to recognize equine dental pain,” she said.

Take-Home Message

Equine dental health goes far beyond routine floating. Dental disease can cause significant pain, affect digestion, impair performance, and alter behavior, said Santi. Owners should watch for signs such as quidding, bit resistance, or sudden aggression. Regular dental exams by qualified professionals, along with informed daily monitoring, are essential for preventing problems and ensuring equine welfare.