Newsdate: May 16, 2025 - 8:30 am
Location: GILROY, California

Within the last two decades, a major change in thinking about geriatric horses has occurred and horses are living longer as a result. Much like human medicine, equine medicine has vastly improved, to the point where horses are living well—and remaining healthy, active and athletic—into their 20s, 30s and beyond.

Horse with dental conditions that may lead to loss of teeth.

The loss of teeth and resulting problems decrease the horse's ability to chew hay and grain and the horse may require a special diet.
© 2008 by April Raine New window.

New drugs, advanced surgical techniques and better nutrition and dental care are changing the notion of what constitutes a senior horse. Unfortunately however, some senior horses 20+ years start to run out of tooth reserves and become deficient in tooth surface leading to teeth and gum issues that result in loss of teeth. The loss of teeth and resulting problems decrease the horse's ability to chew hay and grain and the horse may require a special diet.

Proper deental care beginning when horses are foals can help horses have strong, healthy teeth later in life. Although most horses that lack sufficient teeth for chewing their feed are older, some younger horses may also loose teeth or have dental conditions that make eating difficult and painful.

In some cases because of the shape of the horse's jaws or mouth, a horse may have to chew unnaturally in an attempt to grind up his food. This action can often result in increased uneven wear on the teeth and in some cases generate significant excess pressure on one or more tooth which can result in serious complications including causing teeth to literally be worked loose.

When a horse has missing teeth, not only is the horse's chewing ability compromised, the missing tooth causes an uneven wear pattern because the tooth opposite the gap grows too long and may interfere with jaw movement or bit action.

When a horse has crooked or broken teeth, his food tends to collect around broken or misaligned teeth, and gum or tooth infections can result leading to not only loss of nutritional value of feed, but also lose of additional teeth.

Some horses  have malformations. The lower jaw may be too short, causing an overbite (“parrot mouth”), or too long, causing an under bite (“monkey mouth” or “sow mouth”). These conditions make it more difficult for the horse to chew effectively, and uncorrected malformations allow the teeth to wear in a pattern that forces the jaw into a more severe misalignment.

In aged horses, loss of molars is a primary concern when discerning a cause for weight loss. As time takes its toll on the horse, dentition can become wavy and teeth can start to fall out.

Eventually, if the malformations are not corrected through effective dental care, the horse may lose teeth long before he reaches old age.

All horses eventually wear their teeth down to the root if they live long enough. If a horse cannot grind feed into small enough pieces to swallow comfortably it may cause him to choke.

When a horse does not properly grind his food because of molar loss or misalignment, the food enters the digestive tract in particles too large for proper breakdown by digestive enzymes in the small intestine and microbes in the large intestine and cecum. If this is the case, feed is of little energetic benefit to the horse and weight loss will result.

Receding incisors, another problem common in aged horses, may cause difficulty in tearing grass when grazing. Inadequate intake of forage will result. Aged horses who have spent a lifetime cribbing may be doubly prone to receding incisors.

Why do horses get gum disease and why do they sometimes lose their teeth, especially when they get older? One of the most common causes is the packing of feed between the teeth. A bad bite can cause such packing of feed which results in irritation and often disease of the gums. It is often followed by disease around the root of the tooth causing it to become loose. The horse will typically be prone to colic.

Shortening of the roots, decay and tartar build-up are contributing factors to periodontal disease. Front teeth (incisors) often have feed lodged between them and this is worse if these teeth are not aligned properly.

Most older horses have changes in the size, shape and orientation of their teeth, but broken incisors, “laid over” teeth, loose front teeth, and gingivitis are not a normal finding in an older horse. In fact, these are signs of a serious, debilitating, painful disorder called “Equine Odontoclastic Tooth Resorption and Hypercementosis (EOTRH), a condition that is being noted by many equine dentists.

EOTRH was first identified in 2004. Since then, the veterinary profession has become increasingly aware of it. The condition involves proliferation (out-of-control growth) of the outer covering of equine teeth, called cementum. In addition, many horses also have destruction of the internal structure of the teeth through resorption. As the disease progresses, the front teeth can become loose and crooked, or break off due to weakness and infection.

In addition, the bone of the jaw can become infected. This condition is obviously painful, and one of the first signs of the disease may be the horse’s refusal to bite a carrot or treat. Other early signs include drooling, decreased appetite, or abnormal behavior at the water trough such as rinsing the mouth and repeatedly dunking the muzzle.

Tapping on the teeth may produce a painful response. To diagnose EOTRH, X-rays are necessary. These X-rays of affected teeth show bulbous root structures and dark spots inside the teeth, which indicate resorption.

Careful observation of the changing eating habits of a horse will likely reveal a dentition problem. Slow eating, reluctance to drink cold water, tilting the head while chewing, wallowing food around in the mouth before swallowing and balling up food in the mouth and dropping it all may indicate a tooth problem.

However, some horses may not exhibit abnormalities in food intake or mastication but may still be losing weight from a chronic tooth ailment. Most equine veterinarians are knowledgeable in proper dental care and can perform a thorough examination of the mouth.

Feed the special needs horse individually if needed. Make sure the older or tooth-challenged horse gets to eat his ration and the boss horse is not cleaning up all the feed.

If chewing is difficult, “soups” of pelleted feeds may be fed. Only “complete” pelleted feeds which are designed to be fed without hay should be used since many pelleted feeds are only grain substitutes and do not contain the proper mineral balance to be used as the major or sole source of nutrition for the horse.

Enough water should be added to the pellets to make a soupy consistency (at least 1/2 gallon of water per lb feed) to prevent choke. Hay can still be fed if choke is not a problem, even if most of it is wasted. Access to good pasture is desirable so horses can continue grazing.

However, if front incisors are missing, as in cribbers, or badly aligned, do not rely on pasture grazing for all nutrition. These horses must be fed complete feeds or loose hay and/or hay cubes since they can not graze effectively.

The most difficult is feeding a geriatric horse with no teeth or with very severe tooth damage. In this case feed a slurry of complete pelleted feed and/or mashed alfalfa pellets. Veterinarians recommend adding some long stemmed soft leafy alfalfa hay to the horse's diet. Horses without teeth still want to chew on fiber.

Supply fiber in the diet of all older horses, as soft hay or even beet pulp, an excellent fiber and energy source. Beet pulp soaked, is easily chewed, digestible, and a good source of calcium. Bran mash is not recommended since it is too fibrous, and bulky.

To be continued with Part 2.