Horse Illustrated Magazine

Aging affects every horse, and those accumulated years can cause serious dental health problems that require extra care. Of course, many older horses are ridden regularly and even compete into their late teens and early 20s. There is no “official” age where a horse becomes a senior.

“After age 15 is when we typically see senior dental changes; most senior horse dental problems we see in their 20s, but some are as early as age 15,” says Christine Staten, DVM, a large animal veterinarian and owner of Adobe Veterinary Center in Tucson, Ariz.

Dental conditions frequently found in senior horses include:

◆ Broken teeth
◆ Worn-down teeth
◆ Overgrown teeth
◆ Steps and waves
◆ Periodontal pockets
◆ Abscesses
◆ Infected spaces between teeth (“diastema”)
◆ Incisor disease (equine odontoclastic tooth resorption and hypercementosis, aka EOTRH)

Staten points out that studies show dental problems are more common in senior horses who didn’t have regular dental care when they were younger.

“Routine dental care can decrease or delay the onset of many of these malocclusions [misaligned teeth],” she notes. “Early dental care helps keep growth rate more consistent so the teeth can take that horse into his older years.”

Inconsistent Growth

Horses have hypsodont teeth, which grow and erupt throughout their lives. One reason for senior mouth troubles is the fact that tooth eruption is not consistent.

As the horse ages, tooth eruption can slow down or stop completely as a tooth grows and falls out. Because growth rate is specific to each individual tooth, the mouth can end up unbalanced as each tooth “does its own thing” independent of other teeth.

“Where you get problems is when one tooth may be slowing down, while the tooth next to it is still growing,” says Staten. “Abnormalities like steps and waves develop specifically because of the unpredictable eruption rates of each individual tooth. No horse is going to get into their 20s and have all their teeth growing at the same rate.”

The inconsistency in eruption rate can also cause small spaces between the teeth, known as diastemata. When food gets caught in these gaps, it can be uncomfortable for the horse, but may also lead to periodontal disease. If abscesses develop, infection can spread to the tooth root and even the sinuses.

Regular exams by a qualified provider will catch these and other senior mouth problems and allow them to be corrected. In some cases, extraction (tooth removal) is required.

Equine Odontoclastic Tooth Resportion Hypercementosis (EOTRH)

Veterinarians are seeing more and more cases of equine odontoclastic tooth resorption and hypercementosis (EOTRH).

“This is very specific to senior horses,” says Staten. “It’s extremely frustrating because we don’t know what causes it or how to prevent it.”

She explains that, for unknown reasons, the tooth roots begin to get resorbed by the body, and the body reacts by building excess cementum on the roots of the tooth. As tooth roots become diseased, the front teeth become infected, unstable and very painful. Because the onset of EOTRH is gradual, most owners don’t notice until the horse is in obvious pain.

“The first signs are usually small red dots or ‘pimples’ on the gums above or below affected teeth,” Staten explains. “In later stages, gums start to recede on those incisors and because the roots are thickened, you can see bulging under the gums. It’s a slow process and we don’t know how invasive or painful it will get for a particular horse.”

Treatment of EOTRH requires extracting the affected teeth, which in some senior horses can include all 12 incisors and sometimes also the canine teeth. Radiographs are taken to determine which teeth need to be extracted.

After extraction of diseased teeth, the horse can immediately return to eating.

“Most horses weren’t using their front incisors anyway because it was so painful, so their transition to eating is instant,” notes Staten. “The day of surgery, the horse is eating better than the day before. It is a dramatic-appearing surgery, but the pain of keeping the diseased teeth in is much higher than the potential pain of the procedure.”

The “carrot test” is a simple way you can determine if your horse has painful incisors. If he can use those front teeth to bite and break a carrot, he’s likely not experiencing significant pain. But if he can’t, this is a sign those teeth are in some pain and require dental care and attention.

Nutrition’s Impact on Horse’s Dental Health

When the teeth can’t do their job—because they don’t meet properly, are worn down or perhaps even missing—nutrition is compromised, sometimes dramatically.

Feed must be chewed appropriately for the horse to absorb nutrients. In addition, horses have to go through the mechanics of chewing in order to produce saliva, which is crucial for proper digestion.

Over 23 years as a veterinarian, Staten has found that virtually all skinny horses have dental issues of some sort.

Remarkable Turnaround

Staten was called to a local rescue to determine whether euthanasia was needed for a 19-year-old horse who came in with a Henneke Body Condition Score (BCS) of 1 out of 9, with 9 being most obese.

“He was clearly starved,” Staten recalls. “When I first saw him, I didn’t think he could be saved, but then I looked in his mouth. A top molar had fallen out, and one of his bottom molars had grown into the space [left behind] and was embedded in the gum. He couldn’t even shut his mouth or chew normally because none of his top and bottom teeth touched.”

After Staten reduced the problematic bottom molar to normal size, the horse was able to eat and chew.

“Within four weeks, this horse was a BCS of 5,” says Staten. “He looked like a new horse.”

Staten has also had cases where owners assumed their horses needed to be retired, but their lack of performance was due to dental problems that could be corrected.

Importance of Dental Exams for Your Horse’s Care

The case of the rescue horse underscores the importance of the annual full oral exam. Problems such as this that are far back in the mouth can’t be caught without an oral exam done under sedation using a speculum to closely examine the entire mouth.

Older horses may require “floating” as often, or even more often, than younger horses. Because their teeth are growing differently, they can have sharper and larger points.

“Routine dental exams are going to catch problems when they’re small and they can be more easily corrected,” says Staten.

She recommends senior horses have a complete physical exam that includes an oral exam every six months. This can be scheduled at their wellness check-ups and vaccine appointments.

“At minimum, the senior horse needs a sedated oral exam every 12 months,” she notes. “Every single senior horse needs something corrected annually. We’re not talking about just ‘floating.’ That’s a very important part of it, but we’re looking for abnormalities and other disease processes in the mouth.”

In her practice, Staten has numerous owners who are still riding their horses into their late 20s and early 30s. But even fully retired horses need that annual dental exam.

Keeping up with your senior horse’s dental care can only enhance his golden years—and may even extend them.

Signs to Watch For

Not every horse with dental problems shows obvious signs, but many will show that something is amiss if you’re paying attention. Any of the following can indicate a problem in the mouth:

◆ Dropping feed (“quidding”)
◆ Salivating more than normal
◆ Bad odor from mouth or nostril
◆ Tilting or tossing the head
◆ Mouthing/chewing the bit more than usual
◆ Red spots on gum directly above or below teeth
◆ Failing the “carrot test”

This article about senior horse dental care appeared in the October 2022 issue of Horse Illustrated magazine. Click here to subscribe!