The equine mouth is a dark cavern of mystery. A lot’s going on in there that can affect your horse’s overall health and well-being, but how can you know what to look for when things are going well much less if something’s amiss? Luckily, there are a number of outward signs and symptoms that can help you spot when something’s wrong.

Horse teeth are hypsodont, meaning they erupt continually throughout their lives. Grazing and chewing gradually wears teeth down as new tooth material is exposed at a rate of about two to three millimetres a year.

“The way their mouth is made, the continuous grinding of one tooth on the other is how teeth are maintained and balanced from one side to the other. When things get out of whack, problems start,” said veterinarian Dr. Brian Heide of Sylvan Lake, Alberta. He operates Heide Veterinary Services, which runs the gamut of equine veterinary care, and specializes in dentistry and reproduction.

Warning Signs of Equine Dental Problems

Chances are your horse will experience at least a handful of dental problems over his lifetime. It’s up to you to watch for the following six major warning signs because most horses are quite stoic about their discomfort.

1. Breath that could knock down a horse

What do I notice? Your horse has his head stretched out begging for treats (as usual). Ready to oblige, you’re hit with a sickly-sweet stench emanating from his mouth.

Why is it happening? The smell is basically tissue and/or food decomposing in the oral cavity. Bad breath, also known as halitosis, is more common in older horses, said Dr. Heide, “because, later in life, their teeth wear down to where they’re closer to the roots. Feed can get stuck or impacted in areas of the mouth and that feed can putrefy.” Gum disease and tooth decay also produce halitosis and, he added, “There are situations where abscesses develop near or around teeth and those can infect and have smell as well.” Tooth abscesses can sometimes set off a sinus infection, which may result in a malodorous nostril discharge.

What else? Stinky breath can also indicate intestinal obstructions, gastric ulcers, kidney failure and lung infections.

What can I do? Sounds kind of weird, but get acquainted with the usual smell of your horse’s breath. Then you won’t question yourself when it’s “off.”

2. So. Much. Slobber
What do I notice? A steady stream of drool pooling on the floor beneath your horse’s head. You even notice a tinge of blood.

Why is it happening? In an ordinary day, a horse produces about 40 litres of saliva. Ulcers, dental issues, gum disease, embedded foreign objects – anything
that irritates or causes pain within the mouth – can cause what’s called hypersalivation. This makes your
horse a Drooly McDroolface.

What else? Hypersalivation can also indicate other conditions (some serious) such as: choke, an esophageal blockage usually comprised of feed; ulcers, strangles; guttural pouch disease; salivary gland or tongue issues; facial nerve trauma; and rabies. A reaction to chemicals in plants such as red clover also stimulates over-excretion of saliva.

What can I do? Don’t freak out. The vet will quickly determine whether your horse is suffering from a problem in his mouth or something else with an oral exam, asking you questions about his recent activities and other possible symptoms. Then, if necessary, they will conduct further physical examinations and diagnostic tests.

3. Slimy hay clumps
What do I notice? Semi-chewed hay blobs all over your horse’s stall.

Why is it happening? These quids (noun) are the result of quidding (verb), which occurs when, “hay gets wrapped up in a certain way when the horse rolls the food around in the mouth with his tongue,” explained Dr. Heide. He spits out these squishy hay (or grass) boluses when tooth or mouth problems make it hard for him to properly chew long-stem fibres. Old guys are especially prolific quidders, because, as they age, their teeth become loose or fall out altogether.

What else? Rarely, quidding may indicate conditions involving tongue paralysis or difficulty swallowing, such as neurologic diseases and botulism.

What can I do? Offer him hay that’s soft and leafy or chopped up. Consider feeding well-soaked hay cubes, pellets and/or senior-blend concentrates.

4. Do they make bibs for horses?
What do I notice? Your horse usually drops some feed at meal times, but these days he’s dribbling more than he eats.

Why is this happening? Dropping or spilling feed usually happens for essentially the same reasons as quidding; it’s hard for him to get the food in his mouth and keep it there to chew.

What else? There may be non-dental reasons for his messy meal habits. He’s decided he doesn’t like his feed forsome reason. He’s distracted and looking around while he eats, dropping feed in the process. He feels competition with herd matesat mealtimes and is rushing to eat, making a mess while doing so.

What can I do? If your horse demonstrates terrible table manners at the best of times, check for other eating-related hints there’s oral issues such as: tilting the head to move feed around in the mouth; tossing feed around; a change in eating rate – either taking a long time to finish a meal or bolting it down; undigested food in his manure; dunking his feed/hay in water; hesitancy to drink water, especially when it’s cold. Call the vet.

5. Looking peaked
What do I notice? Your horse has dropped some pounds and his coat is dull.

Why is this happening? Understandably, if his mouth hurts, he might be wary of eating. Also, an inability to chew properly affects food absorption in the gut.

What else? There’s loads of reasons why he may have lost weight – disease and illness, stress, time of year and insufficient feed intake related to the amount of work he’s doing. But, said Dr. Heide, “The first go-to is get his teeth done and make sure he’s dewormed.”

What can I do? Try offering him watery feeds he can slurp down versus chewing. Also give him soft, wetted-down hay. Know his regular baseline weight, so you’ll notice right away when he’s thinner. Call the vet.

6. Riding woes
What do I notice? Lately, your horse is reluctant to take the bit when you’re tacking up. Riding isn’t much fun either. He tosses his head, braces, yaws his
mouth and fusses.

Why is this happening? More than likely the bit is hitting some sharp points or hooks, but any oral-health issue could create resistance and reduced performance.

What else? “More subtle things can happen such as not wanting to collect or do the things he normally does,” said Dr. Heide. “There’s freeness within the mouth that allows that horse to put this head in different positions and to hold those positions. If the teeth aren’t able to slide in a certain way that they need to, then it can almost lock the jaw and make it harder for the horse to do the job it was supposed to do.”

What can I do? Take a break from riding until your vet’s examined his mouth. Get the vet to help determine whether your bit is the right size and shape for your horse’s mouth. Check the bridle, too. Are the straps creating pressure on the soft tissues of the mouth?

Horses need regular oral exams to mitigate problems or prevent them from occurring at all. Dr. Heide suggests performance horses be checked annually, while every two to three years is a good timeline for other horses with no ongoing problems or corrections. “Just like people, horses have variation in how good their teeth are. Some require more [checkups] than others,” he added. “All we’re doing as veterinarians when we look at horses is try to put them back into balance so they can eat well and also ride well.”

Common Equine Oral Health Problems

Hooks and ramps
Tooth protrusions due to misalignment of upper and lower jaws (i.e. overbites and underbites).

Enamel points
Sharp outer edges of upper molars and inner edges of lower molars that are a result of normal tooth wear. These can cause sores, lacerations and ulcers on cheeks and/or tongue and bridle issues.

Diseased, broken or lost teeth
From trauma, wear-and-tear, age – can make chewing painful and difficult, lead to infection.

Wolf teeth
Usually erupt in the upper jaw and interfere with the bit. Blind wolf teeth, those that have yet to break through the gums, can also create bit issues.

Retained caps
Deciduous (aka baby or milk) teeth that don’t shed properly, causing permanent teeth to grow in abnormally or never to erupt.

Gaps between teeth (diastema)
Food and other items can get trapped in the space and eventually decay.

Plaque (tartar)
Crusty buildup at the base of the lower teeth that can trigger gum disease and tooth loss.

Waves, steps, ridges and shears
Uneven and improper molar wear patterns that make chewing difficult and can result in more severe disease and tooth loss.

Incisor (front teeth) abnormalities
Curvatures upward (smile) or downward (frown) and slants (diagonal bite) resulting from abnormal growth of permanent incisors, chewing patterns, missing or damaged incisors, cribbing and wood chewing. These issues may lead to inhibited chewing, irregular molar wear and jaw pain.