Ask the Vet: Straight from the horse’s mouth

What’s up in there? And why’s teeth-floating such a big deal? Dr. Jen Johnson brings us a primer on equine dentistry.(Top photo: Wikimedia Commons)

From Jen:

Equine dentistry has come a long way in the last several years. Since, in general, horses don’t get cavities or excessive tartar build up, equine dental care is aimed more towards maintaining a comfortable apparatus for eating and riding. (Although, I did recently discover a product marketed overseas called “Equident,” a toothbrush developed specifically for horses!) So lets discuss horse teeth, how they develop and why dental care is important.

Horse teeth have a short crowns (tooth above the gum line) and long roots (tooth below the gum line). This is because their permanent teeth are continually wearing and erupting new crown. When there is no more root to erupt into a tooth, that tooth becomes “extinct.” This tends to occur when the horse is around 28-30 years old; this is incredibly variable based on the forage the horse has been eating and the dental care it has received.

Adult horses have four types of teeth: incisors, canines, premolars and molars. The wolf tooth (not pictured) is a vestigial first premolar – estimated to be present in about 15-30% of horses and often removed when it is present.

Most horses should see a dentist for the first time around 3 years of age (or whenever they have to go to serious work with a bit in their mouth). Depending on several factors, your horse may need to be seen every 6-12 months for the rest of his life. Your dentist will let you know when they want to see your horse again.

If you’ve ever watched your horse chew, you will notice that the jaw moved in a circular motion. This causes uneven wear on the teeth side to side, resulting in sharp hooks on the teeth that can cause damage to the cheeks and tongue.

Traditional teeth floating involves rasping down these hooks and points, which makes the horse much more comfortable. As you can imagine, these teeth get very sharp, and can cause quite a bit of damage and discomfort for the horses.

Of course, with horses, nothing is ever simple. There are several different problems horses can develop related to the wear on their teeth and these need to be addressed through proper dental care.

Wave mouth: This is when the occlusal (chewing) surface of the teeth is not flat. Each tooth on the top and bottom are different heights. This occurs from uneven wear and can cause the horse to chew their food with less efficiency. It can also impede the necessary side-to-side motion horses need to chew.

Step mouth: This occurs when a horses loses or otherwise damages one (or more) of their teeth. This results in the opposite tooth having nothing to grind against, so it becomes overgrown. The overgrown tooth can impede normal chewing, and can also damage the opposite soft tissue. This can cause, among other things, abscesses in the mouth.

Depending on the severity of these conditions, it may be necessary to correct them over several visits. Your dentist can’t take too much crown off at once, or they risk exposing the root of the tooth, which can lead to pain and infection.

Consequences of poor dental care

Horses with bad teeth can suffer a range of health and performance problems. First, if their mouth hurts, they will eat less food. Seems obvious but untreated dental disease is one of the most common causes of “unexplained” weight loss in horses. Second, poor alignment of the teeth can reduce the efficiency of the chewing motion. This can lead to poorly digested food. Best case scenario, the horse is just not absorbing all the nutrients, so money is being wasted in the manure pile. Worst case scenario, the poorly chewed food can result in choke, an impaction or other type of colic. There can also be problems with the teeth themselves, ranging from fractured or cracked teeth, abscesses or deep pockets that can pack in food or other debris (leading to infection).

Horses can also experience performance issues with dental problems. Many equine dentists will put a special curve in the tooth that sits behind the bit, called a “bit seat”. This involved rounding the edges of the teeth so there is no sharp surface to catch soft tissue between the bit and the tooth.

When horses flex at the poll, their lower jaw actually moves back in relation to their upper jaw.  A horse with things like step teeth or a wave mouth will not have that forward/backward mobility, making it harder for them to comfortably “come round”. This will, in turn put more strain on structures such as the TMJ and muscles in their neck and back. A horse with a properly cared-for mouth can use their body more correctly.

Incisors…or not?

There is still some debate as to whether horses need their incisors done. My personal belief is that horses can benefit from incisor work when it is done correctly, especially in a horse like the one pictured where the teeth are not equal height. This is clearly an abnormal wear pattern that should be addressed. The other common incisor ailment is when the teeth become so long that they actually prevent the pre-molars and molars from making contact. This means there is no grinding surface for chewing of food. It is uncomfortable for the horse, and presents a real danger of choke or colic. Finally, overly long incisors can also prevent that forward/backward motion of the jaw needed for horses to come truly round.

Not all practitioners are comfortable doing incisors, as it can be easy to “quick” the horse and expose a root. Speak with your equine dentist if you have concerns about your horse’s incisors and develop a plan you’re both comfortable with.

Power Floating & Sedation

Power floating is just that – floating with power tools. Like all things, there are advantages and disadvantages to using hand versus power floats. With power floats, there can be a real danger in over-floating and having heavy, large power tools around a horse for an inexperienced practitioner. There are some major advantages to using power tools. Experienced practitioners can perform more precise and delicate work with power tools. Also, because the work can be performed faster, your horse is under sedation and had to wear the uncomfortable speculum for a shorter period of time.

I also firmly believe that no dental work should be undertaken without sedation which, in most states in the U.S., means a veterinarian must be involved at some point. When done properly, a speculum is used to keep the mouth open, and imagine all that heavy metal swinging around in the mouth of an upset horse. Someone gets smacked in the head and instant concussion – without the benefits of a neat “Oh $h!t” photo to send in to Horse Nation.

Speak with your veterinarian or Equine dentist about your horse, their job and your specific needs with dental care. Ask the vet if they’ve taken any dentistry continuing education or special certification courses. Be sure to get referrals and recommendations from people you trust in your area. Many veterinarians are now choosing to specialize in equine dentistry, and asking one of these practitioners to work on your horse can bring huge advantages as far as experience, training and expertise.

Photo credits (top to bottom)

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