ASK THE VET
Canadian Horse Annual 2016
FLOATING THE TEETH OF HORSES?
by Amy Harris
Hidden away in the depths of your horse's mouth, sharp enamel points on teeth can cause pain, leading to weight loss and training headaches.
A horse has developed a chronic cheek ulcer, which has formed due to sharp enamel points that were not floated off.
Power dentistry, using a drill-like tool, is becoming a common standard of care, particularly for horses who require extensive corrections.
The grinding tip at the end of the power floating device (left) is made of carbide or crushed diamond bits. In some cases, where only minor adjustments are needed, a manual rasp can be used instead of a power tool.
Some owners opt to have their horses' teeth checked annually as part of a routine health exam by a veterinarian. Others, however, don't consider a dental check-up unless their horse appears to have an issue - like difficulty chewing or resistance to the bit.
As is often noted, horses are stoic creatures, which means they tolerate and disguise pain quite expertly. A horse could be suffering from any number of common teeth troubles, and you might never know it. A dental exam will reveal issues such as misalignment, unshed caps (baby teeth), the presence of wolf teeth, fractured molars, loose or rotting teeth and, most commonly, sharp enamel points.
The term "floating" refers to the filing off of these sharp points on the teeth, which develop as the result of the circular chewing pattern horses employ to grind their feed. Dr. Kelli Gilson of Gilson Equine Veterinary Services in Fraserville, Ontario, explained that the lower jaw (the mandible) is narrower than the upper jaw (the maxilla), which creates wear in certain areas while other areas become overgrown. "As such," she said, "horses are prone to getting sharp enamel points on the outside edges of the upper teeth and the inside edges of the lower teeth. These sharp edges can actually ulcerate the cheeks and the tongue, causing mild to severe discomfort for chewing and also for wearing a bit and bridle. They are floated off to make the horse more comfortable."
In the past, all floating was done manually, using a rasp. Dr. Gilson said young horses or those with few adjustments can still be floated manually. However, power dentistry has become increasingly more common. "There are several different brands of power equipment," she explained. "Most have a rotating disc on the end of a long "drill" that can reach to the back of the mouth. Ours is called a PowerFloat and uses either carbide or crushed diamond bits on the grinding disc. These are very sharp, but get dull with use and have to be replaced regularly."
Dr. Gilson said a simple float would involve just removing the sharp edges, while a full mouth equilibration, or balancing, involves also adjusting overgrown teeth (including the incisors) and ridges across the teeth to allow the horse to chew better. "The most common abnormalities we see," she said, "are hooks and ramps, which are overgrown teeth usually secondary to an overbite." These overgrown, misshapen molars can dig into the gums and cheeks, causing discomfort, particularly when a horse is bitted/bridled.
Most owners are not aware that their horse's teeth are sharp, said Dr. Gilson. "By the time it becomes apparent, in the form of abnormal chewing or resistance to the bridle, the problem has progressed and should be taken care of as soon as possible. I recommend a dental assessment by a veterinarian at least once a year, unless it is already known that the individual's teeth need to be done more often."
She added that older horses should be regularly assessed for "expiring" teeth, which are reaching the end of their functional life. "Older horses are far more likely to have a tooth loosen and require extraction. However, the growth of the teeth does tend to slow down after age 20 in many horses," she noted, so they may need floating less often.
"Young horses have other dental problems such as 'caps' [retained baby teeth] and wolf teeth. These issues can be assessed and treated by your vet," said Dr. Gilson. "The horse doesn't have a full mouth of permanent teeth in wear until nearly five years old. Interestingly, some horses, and some breeds, tend to have better teeth than others, and these may not need to be floated as frequently."
Dr. Gilson said a dental exam can take anywhere from 30 minutes to over an hour to perform. The sedative that is administered - for example xylazine, detomidine, romifidine, butorphanol or acepromazine - takes over an hour for recovery. She cautioned that the horse should be monitored following a floating and should not be allowed to eat until fully awake, otherwise they could choke.
"Most horses carry on after the procedure with no side effects," said Dr. Gilson. "Some horses take a few days to adjust to their bite if adjustments have been made. Occasionally, a horse will have a sore jaw and may require pain medication afterwards. You should always inform your veterinarian if your horse has any unexpected problem eating after having a dental procedure."
The veterinarian carefully guides the "drill" around the horse's mouth, removing sharp enamel points, and improving the chewing surface.
In addition to a loud grinding noise, power floating causes the horse's mouth to become "dusty" as enamel is filed away.
WHAT ARE WOLF TEETH?
Sometimes a dental check-up will reveal the presence of wolf teeth, which can interfere with the bit and cause discomfort and, therefore, resistance from your horse. Not to be confused with canine teeth, which are much larger and appear closer to the front of the jaw, wolf teeth are often small and peg-like with short roots (though their size and appearance can vary considerably). Some don't even erupt fully from the gingivae (gums). When they appear, wolf teeth are found close to or right next to the molars. Canine teeth, on the other hand, typically erupt within a couple of inches from the incisors. Wolf teeth, which can erupt anywhere from birth to 18 months, are usually visible by six months of age. The veterinarian can remove the teeth, while the horse is sedated. In these photos below, the veterinarian first loosens the tooth with a long screwdriver-1ike instrument with a curved tip, then pulls the tooth using a pair of pliers. The tooth, including roots, is about one inch long.
A veterinarian uses a diamond chip cut-off wheel instrument to float the incisors. Alternatively, a manual rasp can be used.
Some horses, and some breeds,
tend to have better teeth
than others - these may not
need to be floated as often.
Some veterinarians have floats which include water flushing and suction to keep the mouth clean and cool as they go. Other vets flush the mouth manually during and after the work.