by Marcia King
A young gelding in training suddenly becomes surly and difficult during workouts. An aged mare consumes ample portions of good quality hay and grass, but loses weight. A weanling has some nasal discharge and is fussy about drinking cold water.
Although the clinical signs for these horses are dissimilar, the cause of the problems is the same: dental disorders.
The gelding has very sharp points on his teeth that pinch his mouth while wearing a bit. The senior horse’s teeth have worn unevenly, so she can’t masticate her food properly. The weanling chomped on some sort of hard object, fracturing a tooth that became abscessed.
Horses of every age may suffer from dental problems due to disease, trauma, and congenital defects. In addition, equine teeth (which grow continually throughout most of a horse’s lifetime, but are kept in check by the grinding and chewing forces used to abrade grass and hay) do not always wear evenly and often develop sharp edges or enamel points. That’s why regular dental exams are important for identifying and dealing with irregularities and disorders before they erupt into major problems.
The Inside Story
In most case, dentals exams and minor procedures are conducted in a conscious but calm horse that’s been administered sedatives and pain-killers, says Gordon J. Baker BVSc, PHD, MRCVS, Diplomate American College of Veterinary Surgeons.
Major dental work is done under general anesthesia. “The development of new power equipment to make reduction of edges easier, new gags to keep the mouth open, short-acting mild sedation, and effective analgesics make dentistry much easier and safer for everyone concerned,” he says.
Common problems that occur in any age horse include points, uneven growth, fractures, and abscesses.
Points
Points develop on the outside of the upper arcade and the inside of the lower arcade. This very familiar problem occurs simply because of normal positioning and growth of equine teeth.
If left unattended, points cause pressure and sores in the mouth, making chewing and the wearing of a bit uncomfortable. To treat, points are floated, that is, the hooks and spikes are rounded and leveled down.
Notes Raymond Q. Hyde, DVM, owner/president of the American School of Equine Dentistry, Purcellville, Virginia, “Research shows that routine floating of teeth can increase digestable energy of rations by 20 percent.”
Uneven growth
“In the wild, as horses graze and browse, they use their incisors and cheek teeth in a coordinated fashion, and the teeth continue to erupt at a rate to replace the tissue that’s worn away,” explains Dr. Baker.
“But in a horse that’s stalled and fed short feed or chopped or cubed hay, the incisors don’t wear at the same rate as the cheek teeth. They end up with an overgrowth of the incisors and a reduction of the molars, and the teeth get out of balance.”
Wave mouth and local pain that causes a horse to load one block of teeth differently from another also contribute to uneven growth. Overgrown teeth need to be reduced.
Fractures
A fractured tooth can occur from facial trauma or biting down on hard objects. “Although a tooth fracture does not mend, if the fracture doesn’t extend into the root canal or affect chewing capabilities, treatment isn’t necessary,” says dental specialist Paul Orsini, DVM.
“If the fracture penetrates into the root canal, at some point an abscess will develop and you’ll have to treat the tooth by either extraction or possibly with a root canal.”
Abscesses
“We don’t always know why an abscess occurs,” says Dr. Orsini. “The signs can be highly variable. You may see swelling, nasal discharge, sensitivity to cold water, weight loss, quidding, or pus draining out of the side of the face.”
Milder cases may respond to antibiotics. Severe cases will require tooth extraction or a root canal, the latter which is not commonly performed because of expense and the fact that not many veterinarians are trained to perform this procedure.”
Select Ages
Many problems tend to occur or are identified with particular age groups. Foals and young adults often have problems with mixed dentition, when baby teeth aren’t completely shed and permanent teeth are coming in.
Maleruptions
Maleruptions, where the teeth come in twisted, can lead to misplaced or impaction of developing and permanent teeth, says Dr. Baker. “We try to create an eruption pathway to allow the permanent tooth to come in correctly.”
Retained Dentition
Sometimes a baby tooth doesn’t shed properly, thereby impacting or preventing the permanent tooth from erupting normally. “This is a common problem,” says Dr. Orsini. “We pull out the baby tooth so the permanent tooth can erupt normally.”
Wolf Teeth
Wolf teeth may interfere with the bit, so are routinely removed by many practitioners when the horse is about one year old, says Dr. Hyde. “This avoids problems with the bit during initial training and throughout the horse’s life. Most horses that rear or resist the bit improve immediately following wolf tooth removal.” Although that viewpoint is strongly and widely held, particularly for horses in sporting activities, Dr. Orsini says normally positioned wolf teeth do not always cause a problem.
Parrot Mouth
Parrot mouth or overshot jaw, a congenital condition, is the most common, serious malocclusion in foals. “The upper teeth extend out in front of the lower jaw,” Dr. Orsini says.
“In severe cases, the horse can’t eat normally; it’s unable to bite off grasses because the incisors don’t meet up with each other. Treatment is via braces or an intra-oral appliance to keep the bite ‘open’.
“Wire braces can slow the growth of the upper jaw while the lower jaw grows and hopefully catches up. Success depends upon the severity of the deformity.”
Sow Mouth
Sow mouth or undershot jaw is the reverse of parrot mouth, where the lower jaw protrudes in front of the upper jaw. It occurs less commonly that parrot mouth. Treatment is similar.
Juvenile Tumor
“Juvenile tumor and cyst formations occur as a result of injury or a change in the structure of the tooth, “ says Dr. Baker. If small and noninvasive, treatment consists of surgical removal, cryosurgery, radiation therapy, or laser therapy.
Adult horses have all of their permanent teeth by age five. “This group is more prone to developing periodontal (gum) disease, the same condition that we see in dogs, cats, people,” Dr. Baker states, “usually due to irregularities that have been neglected. As a result, the health of the gum deteriorates, so gaps and inflammation start to occur between the cheek teeth.
“We can prevent periodontal disease by regular attention, but once large pockets and gaps have occurred, we don’t have mechanisms to re-grow gum or bone that supports the teeth. In those cases, we take out those teeth that are grossly loosened and infected and recommend high-energy equine senior feeds, as these horses have a tough time masticating long feed such as grass hay.”
Senior horses, generally described as those over 20 years, may develop wave or step mouth. “There are many contributing causes including missing, damaged, or mismatched teeth,” says Dr. Hyde.
“This stair-like formation from the front to the back interferes with chewing. The waves create short teeth which can wear out prematurely, leading to cavities, tooth fractures, and periodontal disease.” Grinding down the teeth may improve the condition.
Very old horses may eventually wear their teeth down so much there is no tooth surface left. “They may have a small remaining section of tooth associated with the remnants of the roots that can get loose, cause pain, or develop infection,” notes Dr. Orsini.
“Those remnants should be removed.” Horses without adequate dentition need easily digestible food such as senior diets, pelleted feed, or hay cubes, all of which require little grinding.
Regular Exams
Teeth should be examined once or twice a year in all horses and more frequently in performance horses and those susceptible to problems.
“The veterinarian usually looks at the mouth soon after the horse is born to make sure that the teeth will line up okay,” says Dr. Hyde. “This alignment can change with age, so rechecking regularly is needed.”
Dr. Hyde suggests that horses up to age 15 have a dental exam and floating every six months because their teeth grow much faster. “Performance horses between 2 1/2 years and 5 years are shedding teeth, so they may need to be looked at three or four times a year.
Horses between 15 to 25 years have teeth that grow out more slowly, so floating and correction usually lasts a year. Horses over 25 years start to lose their teeth, so a twice-yearly dental exam may be necessary.”
Frequency of exam also depends on use. “A free-ranging broodmare probably only needs an annual exam,” says Dr. Baker. “But a high performance horse should be examined at least twice a year and appropriate measures taken to maintain the dental arcade in balance.
“The reason for this is the tissues surrounding the cheek teeth are tightly applied in the horse and consequently it doesn’t take a very large spike or hook to cause discomfort with the bit. By removing those points, you keep the teeth in balance and head gear won’t cause problems.”
With regular dental care, most problems can be addressed before they become big or irreversible problems.
Making dental exams an important part of your horse’s yearly or twice-yearly routine exam is not just a matter of fresh breath and a pretty smile, but of good health and optimum comfort.
