Mouth Injuries in Horses

Horses can injure their lips, cheeks, teeth, and tongues in all sorts of ways; here's what to look for in these scenarios.

If you watched Dutch dressage rider Adelinde Cornelissen's performance with her mount Jerich Parzival at the 2010 Alltech FEI World Equestrian Games, you know the pair were disqualified after the horse bit the tip of his tongue.

While the injury was minor, even a small amount of blood can turn a horse's foamy saliva an alarming shade of red.

Perhaps you've gone out to pasture to catch your horse and discovered blood oozing from his mouth. You can't see where the blood is coming from, so you call your veterinarian for a more extensive examination. He might have sustained a mouth or tongue injury such as a puncture from a foreign object, an accident with a bit, or he could have an object jammed between the teeth.

Mouth injuries can happen in any horse, whether in elite competition or in our own stables and pastures. We'll discuss these types of injuries in detail here.

"A common injury is being kicked in the jaw or incisors," says Tad Tipton, DVM, of Hagyard Equine Medical Institute, in Lexington, Ky. "This might result in fracture of a tooth or laceration of gums, cheeks, or surrounding tissue. Injury might also be caused by the horse biting the top of a board and jerking back, affecting the incisors and causing dental problems."

"Some mouth injuries are hidden, however, and can fool us," says Melinda Freckleton, DVM, of Haymarket Veterinary Services in Virginia. "We may do a colic exam or try to discover why a horse is uncomfortable or isn't eating. If there's something wedged between the teeth or impaled in the tongue, it may not be found until more common problems have been ruled out."

Bleeding from the mouth is the most obvious sign of injury. "It often looks like there's more blood than there really is, because it's mixed with saliva,"says Freckleton.

Signs might also be as subtle as the horse not eating, not behaving normally, or appearing vaguely uncomfortable. Tipton tells of one horse that was treated for ulcers for 30 days because he was not eating properly and was grinding his teeth. "When the horse came to me I looked in his mouth to check his teeth and saw part of a plastic pop bottle lodged between the teeth and the cheek," says Tipton.

Horses are notorious for finding ways to injure themselves. A fall might result in landing on the nose, splitting the lip, or chipping/fracturing a tooth. "Young colts love to play mouth games with each other, and this can result in injuries," says Freckleton.

Similarly, curious horses chew on all kinds of things. "Injuries can be caused by a horse chewing on a bucket and getting the snap hooked onto the corner of the mouth and tearing it," says Tipton.

Tongue Injuries

Tongue injuries can occur for many reasons, including rough bit use or a horse pulling back after stepping on or while being tied by the reins.

A horse can also accidentally bite his tongue if he falls or suffers a blow or a kick that causes him to close his teeth on the tongue. Tongue lacerations can occur if teeth are sharp, as well. "Usually these cuts aren't deep, but irritation of rubbing against the sharp tooth may cause chronic ulceration and soreness," says Freckleton. "You might not notice the problem unless the horse bleeds."

Tongues bleed dramatically when cut, but this sign might be missed if the horse is swallowing blood rather than spitting it out or is at pasture and the injury stops bleeding before you see the horse. In this type of situation, says Freckleton, "the tongue may heal on its own in an odd position."

A deep tongue laceration can be a very messy situation. "If the lingual artery is cut, there will be dramatic blood loss," says Tipton. "This is an emergency; the horse must be sedated and the wound ligated (tied or bound with suturing material). This can be challenging, however, due to lack of working space inside the mouth."

A cut tongue can be difficult to suture, and the repair can come apart. You can't immobilize the tongue like you might immobilize the sutured skin on a foot or leg with a cast or bandage.

"Mouth tissues are constantly bathed in saliva, which also tends to break down sutures," says Freckleton. "The motion of the tongue itself may undo suture knots. We try to suture a cut tongue, and there are many successes, but there are also a lot of failures."

If a horse bites off part of his tongue, it usually heals well. "As long as the missing part is in front of the frenulum--the little tether at the base of the tongue--the horse usually does well," says Freckleton. "He can still eat. You can't reattach a piece if it's completely gone. If the cut-off portion is still hanging there, we usually try to reattach it. The tongue has a good blood supply, and it's amazing how well it can heal."

Tipton tells of a horse losing the front third of his tongue because the owners tied a tongue tie (used in racehorses to keep the tongue down and forward away from the airway) too tight. "That part of the tongue is gone, but the horse can still eat and drink; the rest of the tongue is still mobile enough for swallowing and maneuvering food," he says.

A tongue or other mouth injury might necessitate a change in feeding, depending on the injury. "You may want to keep the horse on soft feeds that are easy to chew and swallow," says Tipton. "In other instances, however, you need to feed long-stemmed hay that won't get packed into certain areas of the mouth."

Losing part or most of the tongue might change the horse's prognosis for a certain type of performance because bitting will never be the same. "If a dressage horse loses the entire portion in front of the frenulum, for instance, that may be career-ending," says Freckleton. "But the horse could do sports that can be performed in a bitless bridle.

Mouth Infections

Horses sometimes get deep, nasty ulcerations in the mouth from trauma, dental problems, and poorly fitting bits and equipment. "These may become infected, especially in an immunocompromised or older horse," says Freckleton. "A healthy horse probably wouldn't get infected because the mouth has such good blood supply and the wound is continually flushed with saliva."

Signs of a mouth infection are often subtle, such as a horse not eating. According to Freckleton, this also might be an indication that a horse has an abscessed lymph node or a draining tract under the jaw.

Horses don't get as many mouth abscesses as cattle because they do a better job of sorting out foreign material or sharp seed awns that get baled in hay, such as from stickery weeds, foxtail, cheat grass, and other plants. But when a horse is unable to sort them out, these might puncture or become embedded in mouth tissues. In such cases an abscess can develop. Usually you don't find the offending sliver; it disintegrates or gets pushed out with the pus that forms around it.

Lip Injuries

A small lip injury, split, or laceration usually doesn't require treatment because these tissues heal quickly. "When in doubt, call your veterinarian to see if suturing might enable it to heal faster or more cosmetically," says Freckleton. However, "some (severe) lacerations should be repaired as quickly as possible."

Debra Powell, MS, PhD, an assistant professor at The Ohio State University's Agricultural Technical Institute, had a horse at a boarding facility that suffered a mouth injury when turned out wearing a halter. The halter caught on something, the horse pulled back, and the noseband became jammed in the corner of the mouth where it injured the lip tissue.

Lip injuries also can result from aggressive use of a chain shank through the mouth. "If a person yanks too hard, this might tear the corners of the mouth," says Powell.

Inappropriate twitch use also can cause injury, particularly if the twitch has a wire loop. Powell has seen horses with cuts and tears on the upper lip that were deep enough to require stitches. "If a horse is restrained with that type of twitch and pulls away, the thin wire can cut right through the skin of the lip," she says.

The reason oral, lip, and face wounds generally heal faster than wounds on the rest of the body is because there is more blood circulation in these areas. "Surgical repairs are rarely needed because often these tissues realign themselves fairly well," says Tipton. "An exception might be if (the horse also has) a fractured jaw that's displaced; it needs surgical intervention to wire the jaw back into place."

Impalement with Foreign Objects

Horses occasionally get objects impaled inside their mouths. According to Freckleton, although horses are good at sorting out foreign material in their food, once in a while they fail. "Then we end up pulling splinters or chunks of metal out of the tongue," says Freckleton.

Foals, in particular, are notorious for chewing on everything, and they occasionally suffer mouth injuries because of their oral tendencies. "We sometimes see sticks or other things wedged between their teeth, or wedged and stabbed into the tongue, or wedged against the roof of the mouth," notes Freckleton. "Usually you suspect something's wrong because the horse is making mouth faces and trying to dislodge the object. If the horse looks like he's trying to spit something out and can't, you need the veterinarian to look into the mouth."

Powell has seen everything from a 10-centimeter piece of wire embedded under a horse's tongue (which was surgically removed under general anesthesia) to a hypodermic needle lodged in a foal's mouth (which was removed after being located via ultrasound).

Depending on where an injury is in the horse's mouth, nerve damage could result in paralysis. "A major nerve runs under the tongue on either side and may be affected if a foreign object is jammed against it and punctures or lacerates it," says Powell. "If this nerve is damaged the horse has a hard time using his tongue for eating and drinking; tongue action is important for swallowing. Damage to this nerve may also result in paralysis of the lower lip."

Tooth Injuries

Freckleton had an emergency call recently for a horse with a small slab fracture in a tooth. The barn manager had examined the horse's mouth, but couldn't find anything because the fractured tooth was near the back of the mouth. Freckleton speculates that the horse might have chewed on something stronger than her tooth. "We plucked out a small shard of broken tooth, and the mare is doing fine," says Freckleton.

"If a horse tries to bite an inappropriate object, he may catch the lower incisors and break them off, sometimes clear down into the jaw," says Freckleton. "It's usually a stallion that does this sort of thing, but any curious individual may get into trouble."

She notes that young horses might get retained caps (when shedding baby teeth; see page 58 for an illustration of caps), and these can cause lacerations and bleeding if they get twisted or wedged in an abnormal position before they come off. "They can cut the tongue or the sides of the mouth," says Freckleton. "I've seen a tongue with minor lacerations when a retained cap shifted and stayed there awhile, until we popped it off."

Older horses can fracture or lose teeth, which can be uncomfortable and lead to infection.

Take-Home Message

Horses--especially young ones--explore their surroundings with their noses, lips, and mouths. They also can be injured by another horse, a fall, or by chewing on items they shouldn't be. Injuries to the mouth and tongue can also occur as a result of bitting and competition. No matter the cause, prompt attention to injuries, and being alert to the possibility of injury in these areas, can ensure your horse will be eating, drinking, and performing without a pain in the mouth.

About the Author

Heather Smith Thomas

Heather Smith Thomas ranches with her husband near Salmon, Idaho, raising cattle and a few horses. She has a B.A. in English and history from University of Puget Sound (1966). She has raised and trained horses for 50 years, and has been writing freelance articles and books nearly that long, publishing 20 books and more than 9,000 articles for horse and livestock publications. Some of her books include Understanding Equine Hoof Care, The Horse Conformation Handbook, Care and Management of Horses, Storey's Guide to Raising Horses and Storey's Guide to Training Horses. Besides having her own blog,, she writes a biweekly blog at that comes out on Tuesdays.

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